Last update: July 10, 2024

Super-Speed Secrets To A Faster Aquarium Cycle

I think you will agree with me when I say…

Cycling is one of the most frustrating parts about setting up a new aquarium.

That’s not because it’s hard – it isn’t. Especially if you follow FishLab’s step-by-step cycling guide.

It’s the excruciatingly long time that it takes for your tank to cycle that is the issue – sometimes up to two months!

That’s two months before you can safely add fish into your aquarium. It’s a darn long time.

Wouldn’t it be great if there was a faster way to cycle your tank?

Well, I have some good news for you.

There is!

Today, I am going to take you through the different ways you can speed up your cycle. Also, check out my top recommendations to speed up the cycling process and ensure a healthy aquarium

The myth of the instant cycle

Wouldn’t it be great if you could add your fish to your new tank on the same day that you set it up?

There are all kinds of products and techniques that promise to cycle your aquarium in just one day. Yep just 24 hours later, your tank is deemed fish-safe. Or you can use a method called Fish-in Cycle, which means you leave a fish in the aquarium during the cycle.

Some go a step further and claim to instantly cycle your aquarium.

This is what I like to call a beginner trap. If you don’t know any better, being able to cycle your aquarium instantly sounds perfectly realistic.

If you have tried before, then you are fully aware that aquarium cycling is anything but instant.

I have personally heard of beginners who claimed that they successfully cycled their aquarium in under a day. However, after testing their ammonia and nitrites with an aquarium test kit, they discovered that their tank was actually unsafe for their fish.

You see, the problem is that ammonia and nitrites are invisible. And at low levels, fish are often not noticeably distressed. This can fool a beginner into thinking that their tank is safe. Meanwhile, their fish are suffering.

So please, don’t go into this thinking that you can instantly cycle your aquarium – it ain’t gonna happen!

With that said, there are ways to shorten the time it takes to cycle your tank. And best of all, the methods that I cover in this guide have been proven to work.

How do you speed up the cycling process?

Remember how I said that there is no such thing as an instant cycle?

Well, that’s still true. But there are a couple of methods that you can use to kick-start your cycle, drastically shortening the cycle time.

As always, how much quicker these methods make your cycle vary from tank to tank. For some, it will drastically shorten the entire process, while for others it may only shave off a couple of days. Remember… When it comes to cycling your tank YMMV, your mileage may vary. The only constant is patience.

1. Focus on the basics

I’ll be straight up with you:

It doesn’t matter what you do to your tank, you won’t be able to speed up your nitrogen cycle unless you have the basics.

If you don’t have good fundamentals, your nitrogen cycle won’t start or worse, it will stop halfway through – that’s the opposite of fast!

So, make sure you adhere to the following guidelines so that you don’t slow down your cycle…

Keep the pH above 7

This one often catches beginners. If your pH drops below 7, the bacterial growth in the tank slows down or stops altogether. So, make sure you test regularly and don’t be afraid to increase the pH if it drops below 7.

Your master test kit has a pH test – use it!

Don’t turn off your filters

Most nitrifying bacteria lives inside your filter. This bacteria needs oxygen to survive and does so by drawing oxygen out of the water that passes through your filter. If your filter is turned off, you deprive the bacteria of oxygen.

Keep your filter turned on throughout the entire cycling process.

Don’t forget the dechlorinator

While the chlorine and chloramines found in tap water may be harmless to you and me, it’s lethal to the good bacteria.

Don’t forget to use a good water conditioner to remove these nasty chemicals.

Use it every time you add tap water to your tank. If you kill your beneficial bacteria, then you have start from the beginning.

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Watch the heating

Temperature plays a major role in how quickly beneficial bacteria appear during a cycle – 65 to 85 degrees Fahrenheit is the sweet spot. Temperatures below 65F can cause the bacteria to grow 50% slower.[1]

2. Rob an old tank

A cycled aquarium that has already gone through the cycling process will be overflowing with that good bacteria that you are trying to introduce into your aquarium.

If you take some of that bacteria from an established tank, it makes sense that it will speed up your cycle, right?

This method works best if you already have access to a cycled tank. Not sure who to ask? Ask the pet store where you bought your equipment from. Otherwise, you could ask your local aquarium club… There’s at least one in every state!

Remember: Beneficial bacteria coats surfaces, meaning that it does not exist in the water column. Taking water from a cycled tank will not make your tank cycle faster.

Here are four ways you can rob beneficial bacteria from another tank.

Use a cycled filter

The best way, by far, to speed up the aquarium cycle is to install a filter that already contains the beneficial bacteria.

Simply remove the filter from the cycled aquarium and add it to your new tank.

FishLab Update: Good news! Coospider will ship a cycled sponge filter to your door for small price.

Season your filter

The next best way is to season a filter. Simply install your filter in a cycled tank and run it alongside the existing filter system.

After about a week, the beneficial bacteria from this tank establish themselves in your new filter. Now, all that’s left is to move it to your new tank.[2]

Add gravel

Beneficial bacteria also coat the substrate of a cycled aquarium. By taking a cup of gravel from a fully cycled tank and adding it to your own, you will significantly speed the cycle.

Buy some plants

Lastly, beneficial bacteria also coat the surface of plants. If you planned on creating a planted tank, buying plants from a cycled tank could be a great way to speed up your cycle.[3]

Be careful, however, using an established tank to speed up your nitrogen cycle has a major downside…

You could introduce some nasty stuff to your aquarium.

Harmful bacteria, algaes and pests such as snails and hydra could all be hiding.

Now, I must stress that most of these problems are very easy to solve, and it’s a risk you have to take if you choose to use a cycled tank to speed up your nitrogen cycle.

3. Use bacteria in a bottle

Many aquarium brands now offer the concentrated nitrifying bacteria in a bottle to speed up the cycling process.


The idea is similar to the cycled tank method – you add live bacteria to your tank so that they can establish quicker.

Just how effective these products are is up for debate, but many aquarists swear that it helped their tank cycle faster.

Now, part of the reason for the varying degrees of success is that the bacteria in these bottles are not equal. In fact, it’s not the same bacteria at all.

You see, there are different types of nitrifying bacteria. While all are capable of eating ammonia and nitrites, only a few contain the nitrifying bacteria that will grow in your filter.

These are:

When used correctly, these bacteria-in-a-bottle products can significantly speed up your aquarium cycle.

Just be mindful that these are living products. If the bacteria inside the bottle runs out of food (past the used-by date) or the bottles have not been stored properly (excessive heat and cold kill the bacteria), the bacteria could be dead by the time it’s added to your aquarium. And, dead bacteria isn’t going to speed up your cycle.


Using any of the above methods is a great way to speed up your aquarium cycle.

The good news? You don’t have to choose one method over the other. In fact, many aquarists say that combining pre-cycled filter with bacteria in a bottle is the quickest way to cycle your aquarium.

And, they might be right. Using this method, I have frequently seen tanks cycle in less than a week. Pretty impressive, huh?

What did you do to speed up the nitrogen cycle in your aquarium? Let me know in the comments below!

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

Comments (119)

The store where I buy my fish (Franco’s aquarium) and supplies gave me the contents of an old filter sponge (squeezed the filter clean in a litre of cycled aquarium water. This really helped the process. I think you should expect this level of service from your own supplier.

Hi Lauri,

I 100% agree with you. Unfortunately many suppliers would prefer to make a quick dollar and sell you an “instant cycling product” instead. Sounds like you have found a great local fish store!

I have an 80 gallon planted tank with 2 fancy goldfish..(I’m a newbie) I’ve used API quick start,conditioner, little freshwater aquarium salt (as directed on the package) it’s been 5 days and the ammonia has been at 0 and risen up to 1, gone down a little to .25 yesterday.. I have Bio filter and 2 mineral bubblers going.. the fish seem fine, (swimming, eating,sleeping, ect) I just need reassurance this is going well? I’m new to this, and I test everyday.. is there anything I should or shouldn’t be doing during this cycling period? I’ve grown attach to these 2 Goldies, and I don’t plan on adding anymore, since they do produce a lot of waste.. I also want them to have plenty of playing room.. there’s no sign of stress, diseases, or toxicity..

This is stressing me though lol..

Hi Angie,

My recommendation for anyone starting out is to use a fishless cycling method (this way your fish won’t suffer) but since you already have your fish, you have no choice but to fish-in cycle – don’t worry, I have a guide for that here That should answer any questions you have. Otherwise it’s just patience. Don’t worry, you’ll get there 🙂 At 5 days, it’s about time to start testing for nitrites, as per that guide!

Yes I have cycled my tanks this way with no problems. It will cloud the tank water badly (nicely) but it clears up in just a few hours. It is important to add a couple of fish while doing this, so that the bacteria has a food source. Always keep an eye on it by testing the water daily.

Thanks for the informative post. I have 3 small tanks which took varying times to cycle (from 1 month to 6 months for one of them!!)

I have tried various methods and by far the fastest was to use cycled media from one of my old tanks in the new tank. I took a sponge insert from inside my old filter and put it straight into the new filter compartment on the new tank – it was cycled within the week.

I am now setting up a 240ltr (55 gallon) tank which is significantly bigger than my others, and I’m not sure I’ll have enough existing media to help kick start the cycle, however I am going to try putting the sponge insert into my canister and see if helps.

My boyfriend recently bought me a 10 gallon tank. We were both told to have it running for 24hrs and it would be okay to add fish. After of course putting the conditioner in for the tap water and safe start for the fish. The tank has a filter and oxygen. I didn’t know about the cycling process. I set it up on Wednesday and got the fish on Saturday. I bought 4 guppies to see how they would do but now I only have 1 left. I did buy a master test kit. I guess I went wrong and added the fish too fast and skipped the cycling process. Do you know anything about Top Fin® Ready Water Preconditioned Aquarium Cycling Water Conditioner? Because if this last fish dies I have to start over and I don’t want to make a mistake again like last time. Or is there a way I can save this fish before it’s too late? I did test the water the other day. Ph was 7.6 but I got it down to 7.2 and high range ph was 7.4, no ammonia, nitrate, or nitrite.

Hi Ashley,

Unfortunately, big box chains like petco and petsmart have a bad reputation for providing the wrong advice to beginners when setting up a tank.

There was never a chance that you could add your fish that quickly.

Your only chance of saving your fish is performing a fish-in cycle. However given that three of the four have already gone, I don’t like your chances of saving this one.

If he does pass on, you’ll be able to perform an easier cycle – the the fishless cycle.

wrong. You can always add fish instantly. It’s called a fish-in cycle. You just have to do 20% water changes every other day and feed lightly.

Hi Jim,

I’m well aware of what a fish-in cycle is. In fact, my fish-in cycle guide, covers it in great depth. However, this is bad advice to a beginner, as is “20% water changes and feeding lightly” without any regard as to what fish is in the tank. You are exposing your fish to ammonia and nitrite. I’d wager all things being equal, a fish not involved in a fish-in cycle will live longer than one that has. And that says it all.

I agree with you that a fish-in cycle works, but it’s not a good solution for beginners who already struggle to grasp a lot of aquarium concepts such as parameter testing. You are essentially risking the life of your fish. Fish-in cycling is a dated method and should only be used as a last resort, rather than a go-to method.

Never buy the instant cycle bacteria products from store. The bacteria inside are most likely dead from storage. Dr Tim’s is the only way to go. As long as you keep up with 10-25% water changes every other day, it’s ok to have a couple of fish. The bacteria need ammonia as a food source to survive. Fishless cycle you have to add pure ammonia o the tank and keep testing every day. Testing kit is required.

Hi Jim.

Thanks for weighing in.

Did you know that Tetra Safe Start is the same strain as Dr Tims? This is going back quite some time now but Dr Hovanec (Dr Tim) worked for Spectrum Brands owned Marineland while researching the beneficial bacteria. Long story short, Dr Hovanec started his own company, patents were shared and now Dr Tim’s and Tetra Safe Start are the same stuff. But Tetra Safe Start is cheaper and more commonly available, which is why I recommend it.

Thanks for the extra info.

Hi, I have some fish that I got from a school project but I’m not 100% sure how long it will take to have the tank cycled. I set up the tank(January 13th) and set it up with conditioner, heater(around 70 degrees F) and filter running. I also just today(January 14th) brought some of the old tank water home to jump start my tank. The amount of water that I put in filled up about 1/8 of my 15 gallon tank. How long do you think it will take before I can put my fish into this new tank?

I currently have well established 210 gallon, a 75 gallon and 2 outdoor koi ponds. (All are freshwater and have been up and running for years). I recently purchased a 38 gallon that will be solely for my beloved newest 3 South American puffers that are currently in my 210. I have a juvenile Arowana that will eventually get large enough to be a threat to my puffers. I’m pretty experienced in fish keeping but have very little patience. So here’s the thing. In setting up my new tank I decided to give seeding a try. In the new canister filter I placed media (the foam from my koi pond, and the floss from my 75 gal. It happened to be water change day, so I basically just transferred water from my 210 straight into the new tank about 75%. As well as 1 artificial and one real plant from the existing tanks. Also for good measure I tossed in 2 mosquitofish feeder fish that have somehow managed to escape becoming a snack as intended. I use API Master test kit and test AM & PM. As well as the 5 in 1 strips to double check, I also have a seachem ammonia monitor (that I understand may or may not be completely useless) I use it simply as an extra precaution for constant monitoring in case of random spikes.
The tank has been up and running for just over 72 hrs and in all 8 tests my parameters are maintaining at
Nitrate-10/20 (this varies slightly between tests)
Is it possible that I have managed and Instant Cycle or is it still too soon to tell? I know the bb isn’t prominent in the water but I figured It couldn’t hurt considering otherwise it would be going down the drain. At the time I thought it was perfectly reasonable, but now I’m questioning weather the nitrAtes readings that I’m getting are simply existing in the old water as opposed to actually being generated within my biological filter? Long in short I completely understand the cycleing conversion process and that typically one would know that the bb is doing it’s thing once you have achieved and maintained 0 ammonia 0 Nitrites and some NitrAtes, which have been my readings since initial setup. So I guess I’m wondering if I’m just fooling myself with the existing nitrAtes that were in the existing water?

Hi Kellie,

It those are some beautiful fish you have and it sounds like you have a very good handle on things. In all honesty, it doesn’t seem like you need my advice at all and are just looking to bounce your thoughts.

It is very likely you have managed an instant cycle. However, I dislike this phrase since if this is the case, your tank never actually cycled to begin with – the colony of beneficial bacteria is already established and all you have done is transfer it to a new location.

You are quire right, the 10/20 ppm of nitrates is possibly existing nitrate from the water you transferred. I know those two mosquito fish will add ammonia on their own, but with such a small bioload for that tank, it could be some time before you notice your nitrates increase.

The easiest way to tell would be to remove your fish and add 4 ppm of 100% pure household ammonia (be careful here, none of the stuff with dyes, fragrances or scents) You likely already have this on hand, otherwise it’s on the shelf of your local grocery store. If there is no trace of ammonia or nitrite after 24 hours, your tank is certainly cycled. This is probably the quickest way of testing it.

Fish less- I used Seachem Stability as instructed on bottle in a 5.5 gallon tank. It’s been 2 weeks and I’ve done a couple little water changes to lower the ammonia, it was at 8ppm, my ph is 7.7 but still 0 nitrites and nitrates. I didn’t expect it to be done yet but I thought I’d see some nitrites by now. Should I try starting over with a new product?

Hi Jacquline,

If I was in your position, I would drop the ammonia back down to 4 ppm. From here, if you wanted to add a bacterial supplement, use API quickstart or Dr tims one and only (it’s the same stuff) which is a very specific strain of beneficial bacteria, the one that is supposed to appear in your tank.

Once you are back down to 4 ppm, I’d start testing as if this is day one of your cycle.

Also, do you have a filter with biomedia, such as ceramic rings, for the beneficial bacteria to live in?

I just set up my first planted tank. I did have a saltwater tank previously, so I had a base knowledge of testing and cycling. By day 3, I added a couple guppies. My water parameters all tested zero. My LFS chastised me stating my tank had not cycled. I wasn’t so sure. I had carib eco complete substrate, chocked full of bacteria. Added the turbo bacteria stuff the LFS sold. And had a good filter, oversized with huge sponge and ceramic biomedia. I keep testing and have maybe just now got 1 or 2 ppm nitrates. Never detected any ammonia or nitrites yet. I believe it was a instant, or nearly instant cycle. Heavily planted, so I’m sure it covered up some of the evidence of the cycling in the first couple days. I will keep testing and monitor this theory. But if anyone thinks they might try to quick cycle, I believe it’s completely possible.

Hi Michael,

In very rare cases, I have seen near instant cycles. Often in planted tanks. But it requires the perfect setup, something that most beginners would not be able to achieve. Congrats on your success, but a beginner setting up a small tank with a betta for the first time won’t see the same results.

If I were to buy a cycled sponge filter to speed up the cycling, do I still follow the instructions on the no fish cycling page and do all the same testing? Thanks!

Hi Cynthia,

Yes, this is spot on! Although if everything goes well, and you don’t accidentally kill the bacteria on the sponge, then you can probably ignore the suggested time frame in the steps. Also, you might find that you go from testing ammonia straight to nitrates, with nitrites remaining at zero the whole time. But by and large, everything else should be similar.

Hello again Ian,
My daughter is having issues cycling her tank, but lives 5 hours away. I was hoping to give her some of my filter floss from my cichlid tank so she has a solid start to cycling. What would be the best way to transport this media? I probably can pick up a 12VDC air pump if necessary. Thanks

Hi James,

I’m sorry to hear about your daughters cycling problems.

It’s a lot of effort and given you’ll likely need to purchase extra equipment. Many independent fish stores sell pre-cycled sponge filters, which are often cheaper than buying a portable air pump and fish bags. Would it be simpler to source one of these from a fish store near her? Just an option that might make your life a little easier.

Otherwise, you’ll need a fish bag, your tank water + gravel substrate, a portable air pump with an air stone(marina worked best in my aquarium air pump tests – see review section on this site) and a filter media bag.

Fill your bag with tank water, add your media bag filled with gravel + filter floss. This will keep it weighed down at the bottom of your bag, so it won’t float around. Next, add your airstone and position it under the media bag. This will cause water movement to go up and through the filter floss ensuring all the beneficial bacteria gets oxygen, which as an aerobic bacteria, is essential for keeping it alive. Tie your bag up with the airline tubing poking through and keep the airpump on the outside. That’s all there really is to it. It’s going to be a chore, that’s why I suggested the buying a pre-cycled filter method first.

What you suggest is pretty much what I was thinking, except for the weighing down concept. I have lots of extra equipment, and I wanted to purchase a 12 volt DC air pump for use in case of power outage anyway, so it is a good excuse to get that now.

I will ask her about her lfs regarding a pre-cycled filter. Thanks. Much appreciated.

Sounds like you are all over it. I’m glad I could clarify that you were on the right path. One more thing, I’d suggest bringing a spare set of batteries, just in case. Batteries always seem to run out during when you need them most.

Good luck!

Would it be counterproductive to put all three seeding bottles into a tank together? SAfeStart, One and Only, and Nite-Out II?

Hi Charles,

Assuming all bacteria is alive and the bottles have been stored properly, it shouldn’t make a difference. I am unfamiliar with Nite-Out II but the other two contain the same strain of bacteria, supposedly the exact same one that forms if you were to do a slow cycle. Since only so much can colonize your biomedia, adding more shouldn’t help. Going further, if all the beneficial bacteria in each bottle has actually died, it could possibly mess up your water parameters.

Hi there. This is all very helpful, especially the Q&A! We were recently given a 30-gal tall by my mother; the manufacturing tag dated it as 30 years old. Because of its age, and because the silicone was peeling at the edges at ~90%, I decided it better to be safe rather than sorry, and reseal it.

We intend to transfer our betta sorority from our established, planted tank into this one (along with the Amazon Sword, which is massive!) I “pimped” our hob 30-60 filter with “BioBalls,” incremental sponge filters, and BioHome media that has been hanging out in our established tank for a couple of weeks (also, I used appropriate chems in the water to remove heavy metals, etc.)

Today, I added three “feeder” goldfish to the new tank to kickstart the cycling process; I’m hoping that by using the “seasoned” biomedia, they’ll be fine during the process, and can then be rehomed in the goldfish pond where I work. After reading your articles, I intend to dose the tank daily with PondCare’s Chlorine & Heavy Metal Neutralizer (great tip – thanks!)

So, question time!
1.) When should I begin testing parameters in this situation?
2.) I know it’s impossible to pinpoint, but, do you think my method will help speed things up?
3.) Should I go ahead and transfer the Amazon Sword?

Thanks SO much!

Hi Faye,

The fish-in cycle is a very dated method of cycling, it often kills the fish used to kickstart the cycle and isn’t considered humane. These days, we know that ammonia is what starts the cycle, and can add it directly, allowing precision measuring and recording. Fish-in cycle you are waiting for the fish to produce the ammonia and keeping a stable amount is difficult. For more info, check out my fishless cycling guide.

To answer your questions,

I always suggest daily testing when cycling. This way you have an exact understanding of how much ammonia is produced and the rate at which it is rising and falling. It allows you to react immediately to any problems or irregularities as they arise.

Using established tank media always speeds up the cycling process, so it will definitely make the whole process faster, a large group of bacteria multiply much quicker than one or two that are introduced in a fresh cycle. This is the logic behind those “bacteria starter” products, but those don’t work nearly as well as established tank media.

Plants don’t affect the cycle and can be added immediately, unless they are ammonia sensitive. If I recall correctly, the amazon sword isn’t but I suggest doing your own research here.


I have 3 established tanks (a 30 long, a 37 & a 55 gallon). I just picked up a 125 gallon that I am planning on moving the inhabitants of the 55 gallon into (2 Electric blue Acaras & 3 “regular” Blue Acaras). I think they’ll be happier in the 125 (they’re all about 3 inches in length now, full grown is 6-8″). My plan is to break down the 55 gallon and start over once the 125 is established.

I have a Fluvial fx5 for the 125. I was hoping that I could put my established Marineland 350gph hob filter from the 55 on the 125, as well as move the established 60g sponge filter (also from the 55). In addition I’m planning to seed the fx5 with extra media that is in the 5 tank as well as seed it with gravel from the same 55 gallon. I also have an under gravel filter being run by 2 power filters in the 55. I’m not planning on using an under gravel filter on the 125.

My questions are:
1) Would this be enough to hopefully “instantly” cycle the 125?
2) Will the under gravel filter in the 55 gallon be enough to sustain the Acaras until I can confirm the 125 is cycled?

Hi Jared,

It sounds like you have already given this a great deal of thought, which is awesome to see.

1) It’s certainly possible that this will be near instant. Since the bioload of the fish being added is the same, it could instantly cycle it. But if you are not going to add the fish at the same time, then there is no source of ammonia to break down and the established beneficial bacteria will begin to die back without it’s food source. If you are going to add your fish, make sure you test frequently and keep a bottle of seachem prime on hand just in case.

2)I’d be doubtful, undergravel filters are hit and miss and don’t have as much beneficial bacteria since they rely on the substrate to filter your tank (gravel isn’t as porous as purpose made ceramic media, giving the beneficial bacteria less surface area to cling to.)

Hi Ian,

Thank you for your response. I will move the fish in with the filters etc. I haven’t finished preparing the 125. I’m going with a mostly slate tile bare bottom. I’m going to include an area of sand substrate, but mostly slate. I am going for easier maintenance with this tank. I’m going to also move the rocks from the 55 into this tank in addition to some new ones. Cichlids like caves etc. I’m going to add some power heads to help circulate and hopefully push most of the waste into the filters, so vacuuming during water changes is not as intensive and less stressful for the fish. If I set the caves up the right way I’m hoping to minimize disruptions to the inside of the tank during cleanings. In my other tanks I have to dismantle the caves to clean the gravel. I will post an update once it is up and running. I’m hoping to get it running this weekend.

Thanks again for the advice,


That sounds like a very interesting tank, I definitely understand the desire to have an easier to maintain tank. My 4 current tanks takes a good chunk of time each week to keep clean, but I enjoy it. I would love to know more about the success and flaws of this setup once you have spent some time getting to know the ins and outs of it. It sounds fascinating. I hope everything goes smoothly this weekend!

Hi there!
My husband and I had a 30 gallon tank that had been running for about a year and a half and only had 4 black skirt terras in there since the rest of our much older fish (from our previous smaller tank) had died. I didn’t know as much about the nitrogen cycle as I do now after getting a new 60 gallon tank for my husbands birthday. I made him promise that we would go slow and not add in any new fish until it was cycled. But he got the best of me and we have added some Cory cats, a few ghost shrimp, and a few other little tetras and a dwarf blue guarami. We used the existing gravel from the previous tank, and hooked up the existing filter and the new marineland one and ran them in tandem for about a week. I even took some of the cruddy stuff from the old empty tank and put it directly into the new filter hoping it would do something to help.
This was about 5 week ago. All the fish are also a still other than one Cory cat that we just lost yesterday. We have been doing daily/ every other day water tests with the api kit. The ammonia is generally between .25 and .5, nitrites have always been at zero and we about a week ago used the safe start and our nitrates went from zero to around 5-10 (forgive me I’m trying to do this from memory). Our ammonia has never gone above .5 and if it does, we do at least a 25-50% water change. I have a few questions if you don’t mind.

1. When adding water, if we put in a dechlorinator first, can we use one of the hoses (one that connects to the faucet that can drain water and add water) and add water directly to the tank, or should we put it in a bucket and dechorinate it first before adding it in?
2. When we added tap water when filling up the new tank is it possible we killed all of the existing bacteria from the old free and gravel and are basically starting from scratch? I’m just curious to know when I may be able to relax knowing the fish are all safe! Lol
3. We moved our 30 gallon down into our bedroom and got a brand new fluval filter and new gravel. We are doing a fishless cycle and have been dosing with ammonia (believe it or not, dollar tree was the only place I could find some without anything added to it!) the ammonia is around 4ppm and nitrites have recently spiked way high, like off the chart high. My husband thought it might speed up the process if we added the safe start to this one as well so he added a bottle last night. The ammonia went down to around 2ppm over night but nitrites are still high and nitrates are around 80ppm? I am wondering where we are in the process for this one since the nitrites are way high now and ammonia still hasn’t gone down to zero. We have not dosed it with ammonia in probably over a week, and the tank is probably maybe 3 weeks old now? Was adding the safe start helpful for speeding up the process now! Is the ammonia still high because maybe there is food decaying from when we originally were trying to build up ammonia?

Thank you so much for any help!!!

Hi Sheri,

Those are some good questions. I’ll start by saying that if your ammonia is readable, then something isn’t right, either your tank isn’t cycled yet or there is something else responsible for the ammonia spike.

1. Yes, when using a water changer system, you add the dechlorinator just before you turn on your faucet. For a 60 gallon, I’d use a water changer over a bucket, you’ll need a few bucket trips at this size.

2. If you didn’t dechlorinate the water prior to adding the gravel then yes, the bacteria in the gravel are most likely dead.

3. When readings get off the chart for a fishless cycle, I like to do a 50% water change or two. Each 50% water change will roughly the amount of nitrite and ammonia in half. You might have noticed that as the readings on the color chart increase, so does the distance between ranges. Even though it reads 80, it could be anything from 80 – 160. Getting the reading back down will allow you to see how quickly it rises and determine if anything is amiss. Just be mindful that you will need to re-dose with ammonia as a water change also dilutes this too. While there is no need to add bottled bacteria during a fishless cycle, It shouldn’t cause it to slow or stop either.

Hey there, great info! I’m an aquarium novice and had never even heard of cycling – I just set up my tank with water and substrate today and I was excited to add my axolotls tomorrow… but now I feel like I need to cycle first! But my question is… what should I do with the axolotls in the meantime? They are in a Tupperware container… can they just stay put with full water changes every other day until the tank is ready? Just what should you do with your aquatic creatures while their tank cycles?? Thanks!

Hi Carley,

Admittedly, Axolotls are a little out of my area of expertise. However, I would assume it would be similar to fish in that you need to perform a fish-in cycle. The ideal is to not purchase tank creatures until your tank has cycled, but if it’s too late, then a fish-in cycle is the only way. I’d research further to confirm this is also the solution for axolotls.

axolotls are amphibian & not fish, so cycling is less of an issue, but should still be monitored for water quality parameters.

I had to restart my 30 gallon tank. I used the good established filter from my platty tank and I added bacteria and have the fresh water master kit. I got all my levels reading normal and put my 3 goldfish back in the tank but they are still acting stressed out! Am I missing something?

Hi Casey,

There isn’t much information to go off here. It’s possible that your tank is too small for your gold fish. They need more room than you think.

With axotlols you tub them and do daily wager changes with prime, if you put the lotls in the tank while cycling they can get serious ammonia burns and they also are very susceptible to stress x

Leaving a glass water out in each nigh and checking for ammonia and the cats water too have a high ammonia level in the morning. Google listed the info.about the three kinds of amiona types.This as been making me nuts. Do purchase household amiona and go from there..

Hi Ruth,

I’m not quite sure what you are asking. If you want a source of ammonia for your aquarium, you can use a store bought variety (without any additives like perfumes and foaming agents) or one made specifically for aquariums.

When dust particles in the house hits water it turns to amiona three. Only checked night samples. Have API master kit. I did fish in tank cycle and had to dohalf water changes daily to keep amiona level down and used prime too.Want to cycle 5 gal tank, Have small betaI. Little more time to cycle his tank. Will amiona that is type one over ride amiona 3 and give me a break. Just call me crazy. Hope head isn’t swimming. Thank you

Hi Ruth,

Unfortunately, I don’t know anything about dust and ammonia. It sounds a little far-fetched to me that it could be used to cycle a tank to any degree. Just use the bottled stuff – people have open topped tanks and use bottled ammonia to cycle.

Hello! I have “Betta” fever again! My Kenji will be 1 year old soon!! I was wondering if I could use a gallon of his change water to start my new 3 1/2 g tank? Also, I would use his filter and buy him another?! I only use Spring water gallon.

Hi Jim,

Out of all the methods, using tank water is probably the slowest way to seed a new aquarium. You see, the beneficial bacteria that establish themselves when cycling your tank are clingers. They don’t float around, the cling to the surface of your filter media.

I highly advise against using his filter. If you remove it you will crash the cycle in his tank. Your best option would be to buy a separate filter and run them alongside each other for a few weeks. This way the beneficial bacterial will build up in the new one, allowing it to become established for when you set up your new tank. Even this won’t allow you to “instantly” cycle your new tank, but it should dramatically speed it up.

How big is enough to put small beta in 5 gal. tank.Dont want to harm him…Best information I have yet on setting up a tank and thank you for your patience .
Addict to beta fish. Is there a meeting place for help, like AAA? just joking.

Hi Ruth,

Do you already have the betta in your tank or are you setting up a tank for a betta?

If you don’t have the fish yet, You would perform a fishless cycle with ammonia using this method. You add ammonia as per your test kit.

If you already have your betta, you would use this method instead. In this case, you keep an eye on the ammonia that your fish produces.

Hi Ian,

Thank you for this article! I’ve recently adopted a betta that has apparently been living in one of those 1/2 gallon novelty containers with unconditioned tap water for about 9 months (the length of time the previous owner had him). I’m totally new to fish ownership, so today I’m going to be buying a 5 gallon tank and whatever accoutrements I need.

My one big concern is that I will shock the poor guy when I transfer him to a new environment, since he’s been in the other tank for so long.

1) Do you think I should complete a full fishless cycle in the the new tank, and keep the betta in the original 1/2 gallon tank while that happens? I obviously am keen to get him out of his horribly tiny bowl as soon as possible, but again, I am afraid of hurting him.

2) If you do think the above is the best course of action, do you have any tips on how to clean the 1/2 gallon container and treat the water with the fish inside? The tank is currently cloudy, I am pretty confident from the state of it that the previous owner didn’t clean it. I want to improve the conditions in the smaller tank while the betta waits to be transferred to the larger one, but again – I’m a beginner and am nervous about changing any conditions.

I look forward to your advice!

Hi Maggie,

It’s an interesting one. Read up on old tank syndrome, essentially, any changes you want to make should be done slooooowly. In your case, there is no clear outcome as the risk of shock to your fish is real whatever direction you take. The first thing you want to do is test the water inside his tank (you’ll need a test kit for cycling anyway, API Master Test Kit is affordable and effective) to determine just how bad things are in there. If it’s tolerable, I’d leave him in that small tank while doing your fishless cycle. A fish-in cycle is very stressful and if he has already been kept in poor water, he may not make it through the experience. In order to improve the state of the tank, slooowly make improvements. Say 10% water changes each day (don’t forget the water conditioner) and monitor the water quality with a test kit. It’s going to be slow, but by stepping carefully, you may be able to save this fish. Just be mindful that if you do lose this fish, it’s not on you, fish often don’t show signs of stress and can look “normal” even though it may be suffering right now – in some cases, they are beyond saving despite everything looking okay. I’m not saying this is the case, I just want you to be prepared, as it sucks when you do everything right and still can’t save a fish. Good luck!

For the first 3 weeks we did Fishless cycling with the Ammonia source. And got a bloom (couodnt see inside the tank) for a couple weeks. Ammonia levels stayed at 8 the
entire time.

We were told to so a water change so we did just to the top of the gravel. And added water conditioner and stress coat plus.
Couple days later added 3 hardy fish (blue Tetra glofish).

My main question is did the cycling start over because we did the major water change? Or is the cycle continuing on?

Hi Joyce,

A white cloudy bloom is typically normal in the cycling process. The majority of beneficial bacteria is found in your filter (it’s not free-floating in the water. If your filter was not left to dry or swapped out, then the cycle shouldn’t have restarted itself.

Hello Jan once again it’s Ruth and it’s not about ammiona. A week ago started cycling 10 al betta tank with fish in. Used one bottle of Terta plus a d did not dose with Prime. When the ammiona got to high I did forth water change. Only reading is were the ammiona readings. Started using Prime and Stability Thuresday and tonight makes dode three. Chasper the white betta seems to bei ok. ay and has a good appetite. The readings today were ammiona 0.25ppm, nitrites 0 and nitrates 40ppm. I rechecked and still 40ppm. How can this be? I will never do a fish in cycle. Thank you so much all you do to make our water babies healthy and happy.

Hi Ruth,

Based on what you have said here, it all sounds positive, congratulations on your hard work!

In some cases, you might find that your cycle “skips” the second phase – that is to say that the nitrite eating bacteria establish themselves instantly.

If your nitrate levels are going up and your ammonia levels are constantly going down, then you are experiencing a normal cycle. Just be mindful that as you progress up the color chart, the gaps between the readings get larger. This can make it seem like your cycle may have stalled, when in reality it’s the shortcoming of the color chart. If you are worried about this, a water change will get the nitrates back to lower levels. A 50% water change would reduce ammonia/nitrite/nitrate by roughly 50%.

Hi thank you for this information, I have a 160L tank which is for my axotlols, they’re currently tubbed and just wanted to say that it’s safe to keep axotlols in a 30L storage tub and do daily water changes but they need an air stone and a hide, also obviously you have to use prime. My ammonia has been at 4.0 ppm for two weeks so I’m going to try and buy some of the “in the bottle” stuff tomorrow and hopefully this could help, im also going to ask if they have any established filter media in the shop I can have (worth a try). Just wanted to give some info about the axotlols as I saw someone comment, theres lots of info about tubbing axotlols as it’s a go to for when they’re ill as you can keep the water extremely clean compared to a tank 🙂

Hi Melissa,

Thank you for sharing your wisdom on Axolotls. I had no idea that tubbing them was so common, I enjoyed reading up on that!

Two weeks is a long time to go without seeing a hint of nitrite – does your filter contain biomedia (like ceramic noodles) or a sponge for the beneficial bacteria to live in?

Hi Ian,

I have a 17 gallon tank and I’m currently on day 5 of the fishless cycle. I am a beginner and your guides/site have been very helpful to me. Of course, I’m still very confused about a lot of things so I hope you can help me understand the whole process better.

1) The shop I bought my tank from recommended adding bio rings to my filter and Continuum Aquatics Bacter Gen-F in the water to quicken the cycle. He did not mention ammonia. Do I still need to add it if I’ve added Continuum?

2) At the last reading, my ammonia was 0 – 0.25ppm, PH was 6.8, Nitrite was 0 and Nitrate was 5ppm. What should the ideal levels be when the cycle is done and it’s safe to add fish?

3) My friend is moving away soon and giving me her fish (guppies, tetra & red swordtail). Is there a safe and harmless method to transfer the fish from her tank to mine without shocking them? How do I acclimate them to my tank?

Hi Aimee,

I’m glad you have found the guides useful and I’m happy to answer any further questions 🙂

1)If you are doing a fishless cycle, then I recommend using ammonia. Continuum is essentially bottled bacteria, It *can* make the cycle move faster, but there is no guarentee.

2) You want ammonia and nitrate to remain at zero with nitrate ideally being below 40 in a non-planted tank (under 10 is ideal) Nitrate will continue going up, even after the cycle. This is why we perform water changes, to get it back down. The 5ppm nitrate you are measuring now is probably from your tap water. You can test this by measuring your tap water for nitrates before you add it to your tank.

3) Look up “drip acclimatization”, unfortunately I do not yet have a guide on this on the website, however there are plenty of youtube videos and wbesites that talk you through the process. However, you would only want to add these to your tank after the cycle is finished.

Thanks Ian! Just a few more questions 🙂

1) I live in Asia so I was unable to find ammonia or Fritz Pro Ammonium Chloride but I was able to find a generic brand. I was assured it’s pure Ammonium chloride but unfortunately, it doesn’t come with any instructions. How much do I put in for a 17 gallon tank to kickstart the cycle? And how much do I need to add as the cycle progresses?

2) What should the nitrates level be if I have a planted tank after the cycle is done? I have plants and substrate.

3) This is for future reference but how often am I supposed to replace my tank’s filter sponge? Mine is a piece of rectangular white (felt cotton I think) sponge kept in an internal filter over bio rings. A friend said it contains the good bacteria so she hardly replaces hers and just washes it in tank water but I can’t imagine a brown, mucky, grimy sponge is any good for the fish too? And how do I go about replacing it so I can transfer the bacteria to the new sponge?

If it’s pure, then ammonium chloride is roughly 32% ammonia bu weight. This means that to reach 2 ppm, you would need 6.3 mg/L. Of course, this relies on the ammonium being pure, so go slow when adding it, just in case. For dosing instructions, check out my fishless cycling guide.

The right nitrate levels will entirely depend on the plants you have in your tank. If you google the plant+aquarium you should see many care sheets explaining the ideal water parameters and how to best raise them.

In your filter, you have biomedia (ceramic rings) this is where the bulk of your beneficial bacteria will live. This allows you to dispose of the mechanical filtration (sponge) more readily, without it affecting your tanks cycle. However, those white filters soon turn brown, but the color alone doesn’t mean you need to toss it in the trash. You replace it when it begins to clog or fall apart – otherwise a quick rinse in the water you siphoned out of your tank during the water change will get rid of most of the gunk. If it’s the sponge that came with your filter, it will likely fall apart quickly, aquarium sponges that you cut yourself are often cheaper and better quality.

I hope this helps!

Hi Ian,

Thanks for your reply! So I started a new fishless cycle in my 17 gallon with added ammonium chloride and I got it up to around 4ppm on the first day. PH was above 7.

I tested my PH today (day 4 now) and noticed that it dropped to below 7 (around 6.6). Ammonia was around 3ppm. So I did a 20% water change and the PH is now back up to either 6.8 or 7ppm. My ammonia is now 2ppm.

I’m pretty certain the drop in ammonia is due to the water change so do I need to add more ammonium at this point (or anytime I do a water change) to get it back up to 4ppm? My nitrite is still 0ppm.

I will re-test again later under better light but if the PH reads 6.8, can I do a bigger water change? Say 40 or 50%?

Your step-by-step guide is a big help but how I wish cycling a tank was easier for us beginners!

Hi Aimee,

Your thoughts are correct here, every time you do a water change, you’ll notice ammonia/nitrite/nitrate drop. For example, A 50% water change would *roughly* drop these readings in half. While cycling, you’ll need to redose ammonia after each water change

If your pH is dropping that quickly, it’s possible you have soft water. I’d keep an eye on this, but if you find yourself having to perform water changes every few days to keep it constant, you might have to read up on “aquarium kh” and how to buffer it – simply put, increasing the hardness of your water stops the pH from dropping as quickly.

Thanks for the kind words – I know it can seem like a lot to take in, and lot’s of waiting too, but it’s worth it. Hang int here!

this is meant as advice for speeding it up but you advise against pest snails which would speed up the cycling process. why is that do you just not like snails?

Hi Joshua,

Good question!

I like snails. But the pests that hitch-hike are a chore to maintain and can quickly grow to plague proportions. Pest snails won’t speed up the cycle any more than these other methods and are just another problem for you to deal with once the tank is cycled.

Hi Ian!

It’s Aimee again. My PH has dropped overnight from 7ppm to 6.6ppm again! So following your advice, my KH test kit is on its way.

I decided to read your guide on fishless cycling again and I just realized I may have made a mistake. You wrote “Fish tanks less than 40 gallons: Add Half a teaspoon of Fritz Ammonia (2 ppm).” I have been dosing my 17 gallon tank to 4ppm of ammonia. Am I only supposed to get it to 2ppm? Is the high ammonia reading the reason for the sudden drop in PH?

I forgot to mention I also have a cycled tank with tetras and guppies and the PH is constantly 7.6ppm. Same water source. Not sure if that’s useful information.

Hi again Aimee!

That’s a rapid drop. If you test the KH of your tap water before adding it to your tank as well as your tank water, you’ll know what you are dealing with. If you do have soft water, I always recommend checking in with the local fish store (not a big box one, like petsmart or petco) as they will use the same tap water as you and likely have a cheap and affordable solution they use on their own tanks.

Adding 4 ppm shouldn’t hurt your tank on the pH level. Although nitrites and nitrates are acidic and do slowly lower pH, it shouldn’t drop them to the point where they stablize at 6.6 (it would keep dropping)

That IS useful information. You might have just made your life considerably easier in regards to narrowing down this cause. It means it’s very likely that something inside the cycling tank that is responsible for the pH dropping. Is there anything you are doing different between the two tanks? Did you use different products on the other one? The KH test kit will also let you know the difference in carbonate hardness between the two tanks. If the pH is stable as you say (and I recommend checking it across a few days to make sure) then the answer could be here 🙂

Hi Ian,

Thanks for your advice. Tested my tank and tap water and KH was low (1 drop to turn yellow) so I added half a teaspoon of Seachem’s Alkaline Buffer and it’s now at a good 7.6.

My current readings:
PH: 7.6ppm
Ammonia: Between 1 and 2ppm
Nitrite: 2ppm
Nitrate: Around 30ppm

Does this mean I’m nearly at the end of the cycle? Following your guide, all I have to do now is continue dosing ammonia to keep it between 1ppm and below 5ppm and wait until both ammonia and nitrites are 0ppm, am I right?

Also, I noticed today I have a ton of teeny tiny snails stuck on the glass of my tank and brown eggs on the plants. I removed the plants, ran them under running water and removed as much as I could. I still see a few whitish sacs on the glass which I remove and squish by hand. Are these snails/eggs harmful to the cycling process? How can I remove them for good?

Hi Aimee,

Yep, you have that correct. More waiting and you should be there. Well done on making it this far 🙂

Pest snails are common hitchhikers on plants, the easiest way to stop them is prevention. There are plenty of guides on treating plants to prevent hitchhikers online. Since your tank is cycling, and you are not adding any food, the easiest way would be to wait for these to die off. Just be mindful that if they all die at once, and there are a lot of them, they may cause an ammonia spike. A water change and gravel vacuum will fix this. Once they are in, you’ll likely forever have a few but if you are properly maintaining your tank, the population will never get out of hand, and they will help clean up waste like dead plants – a natural cleanup crew.

Otherwise you can add a snail killer (typically copper based) but this will require you to remove all traces of it through chemical filtration before you add fish.

Hi Ian!

Just when I think I’m nearly there, I think i’ve hit a snag! Posting my readings below:

14 July
PH: 7.6ppm
Ammonia: 1ppm
Nitrite: 5ppm
Nitrate: 30ppm

Added 1/8 tsp ammonium chloride

15 July
PH: 6.8ppm
Ammonia: 2ppm
Nitrite: 2ppm
*I forgot to test Nitrates

Added Alkaline Buffer

16 July
PH: 8.12ppm
Ammonia: 1ppm
Nitrite: 2ppm
Nitrate: 5ppm

17 July
PH: 8ppm
Ammonia: 0.5ppm
Nitrite: 2ppm
Nitrate: 5ppm

Added slightly less than 1/4 tsp ammonium chloride
1 hour later, ammonium: 4ppm

18 July
PH: 7.6ppm
Ammonia: 0.5ppm
Nitrite: 2ppm
Nitrate: 5ppm

Added 1/8 tsp ammonium chloride
1 hour later, ammonia: 2ppm

19 July
PH: 7.6ppm
Ammonia: 0.5ppm
Nitrite: 2ppm
Nitrate: 5ppm

Added 1/8 tsp ammonium chloride
1 hour later, ammonia: 2ppm

I am now dosing my tank with ammonia daily but my nitrites seem to be stuck at 2ppm and nitrates dropped from 30ppm to remain at 5ppm for the past few days. Does this mean my cycle has stalled? What can I do at this point?

Hi Aimee,

Thanks for your easy to follow readings 🙂

Nitrate doesn’t drop like that unless you do a water change or are removing it with chemical filtration. Have you done either of these? If not, I’d double check your testing.

Hi Ian,

Nope, no water change or any chemical filtration. I haven’t been doing anything except dosing it with ammonia daily. I am getting these teeny tiny white bugs stuck/crawling on the tank glass but no other changes otherwise.

But now that you mentioned it, whenever I open bottle no.1 of the Nitrate test, I get a whiff of something like rotten eggs. Is this normal? The expiration date is 2023 and when tested with my friend’s tank water, he gets 20ppm.

On a side note, I can’t dose my tank with ammonia fast enough. I added ammonia at 3pm yesterday to 2ppm and when I tested it at 12pm today, it was down to 0ppm. Nitrite remained at 2ppm and nitrates is still 5pm. You mentioned in your guide that if my ammonia goes down to zero, the bacteria starves. Does this mean I now have to start my cycle all over again?

I am really clueless at this point what to do. I’ll order a new test kit but should I do a partial water change while waiting for it to arrive? Or should I just do a full water change and start the cycling from scratch again?

Hi Aimee,

Test kits normally have a chemical smell. If it’s measuring your friends tank, I’d say there isn’t anything wrong with the test. Did he have a test kit you can borrow?

It’s very rare that test kits are faulty, but it is still a possibility. A good way to check is to take a bottle of tank water to your local fish store. Many of these offer water testing services. Not all do though, so if you plant to do this, ring ahead! It’s a good way to double check.

All that ammonia has to be going somewhere, so I have a suspicion your nitrite levels at least are higher than you think, unless you are using something in your filter that removes ammonia (like zeolite) the only place for it to go is to convert into nitrite then nitrate.

I don’t think you need to start cycling again. I think we need to first figure out what your actual water test results are and go from there. After all, if you start from scratch, you may bump into this same problem again.

Hi Ian!

Tested my tank with my old & new test kits as well as my friend’s kit and results were the same.

PH 7ppm
Ammonia 0 – 0.25ppm
Nitrite 1ppm
Nitrite 5ppm

As usual, the ammonia dropped from 4ppm after less than 24 hours. To be honest, the nitrites from my previous tests could have been 2ppm or 5ppm, I couldn’t really tell the difference from the chart. Is the slight drop to 1ppm a good thing though? Nitrates are still not budging.

At this point, I’m not even sure where i am at the cycling stage. Should i do a partial water change or leave it for a few days to see if there are any changes?

I was also hoping to add some crushed coral to my tank to increase the pH naturally. Am currently using seachem alkaline buffer but I find it fluctuates after a few days. When would be the best time to add the coral? Now? Or wait until the cycle is done, which I really feel could be never lol!

Hi Again Aimee,

This is such a mystery! Nitrites dropping is a good thing, the end result is we want them at zero. The nitrates not budging has me stumped. Unless your cycle has stalled (in which case ammonia and nitrite wouldn’t be moving) something is amiss.

So here is an experiment. If you take 50% of your tank water and add 50% distilled (or RO) water, when testing, it will drop your readings by 50%. If your test kits are still reading the same with this method, then something in your tank is causing the kits to return an incorrect reading.

On the crushed coral, my personal suggestion would be to add it after this is all done. You don’t want to add *another* variable into the mix when things are already proving to be difficult.

Have faith, your cycle will be done 🙂 For some reason we are just taking the “scenic route” to get there.

I’m so sorry that your cycle is proving to be a difficult one.

Hi again Ian,

Finally some change! Good or bad I’m not sure lol.

I’ve been dosing my tank with ammonia every day to about 2ppm. Takes less than 24 hours to get to 0ppm.

Nitrite is around 2ppm (or 5ppm?) and hasn’t really budged.

My nitrate was between 20 to 40ppm yesterday but 24 hours later, it has shot up to 160ppm. I thought my nitrite should have gone down in order for the nitrate to go up. What do I do at this point?

Do I have to do a water change? If yes, how much should I change? Or do I just leave it since it’s a fishless cycle. Do I continue putting ammonia?

Hi Aimee,

It’s possible that the test kit was being misread, as nitrate couldn’t spike that high in such a short amount of time. At this stage, you want to get the nitrate back down to readable levels. Since the card maxes out at 160, you don’t really know what your nitrates are at (they could be 400 for all we know. You’ll need to do a few 50% water changes to get it back down. Let the water sit for half an hour before retesting. If it’s still high, do another 50% water change.

Once you have it way back down, (ideally under 40) I’d add ammonia and re-check. Keep in mind that when you do a water change, you are also diluting the ammonia and nitrite in the water. So once you are done with the water change, you’ll want to re-dose with ammonia.

Hello Ian!

I figured it would be best to come over here to comment even though I have another thread going with you about my cycling issues lol. I just wanted your opinion on Fluval Cycle Concentrated Biological Booster – I dosed the 2 small tanks with TSS and that brought my ammo from 0 to .25 (after 4 weeks) 0 nitrites and 10 nitrates.

I am assuming thats a good one since you requested it – read a whole lot of reviews on this product as well and it too had great reviews just like TSS.

I finally took your advice with the tank I have been stuck with between 2-5 nitrites and did about a 75% water change. I used my dechlorinator and dosed each gallon with aquarium salt – I have my little girl back in the cup from the store so I can acclimate her with the new water. Hopefully, this comment gets approved today so I can get your opinion because I trust you!

I know that the filter media and sponge holds most of the bacteria so I hope I didn’t crash the cycle by doing such a large water change, but I also took gravel from my 10 gallons cycled the tank and added which I thought would be good!

I ordered TSS which will be here on Saturday but if you have heard about this Fluval cycle and think it could be equal to TSS then ill go ahead and add it.
FYI my tap water has an ammo reading between .50 and 1ppm after adding the de-chlorinator and salt – the dechlorinator I use is the small little bottle for betta fish and it says that it detoxifies all toxis metals etc such as ammonia, chlorine, and chloramine so my thoughts are that it gets rid of the TOXIC ammonia and I am only seeing ammonium since the kits don’t tell the difference. I usually use Prime but all the BB including TSS say that you cant use prime 24hrs prior because it will ruin something (lol I know something is not very specific but I am still learning all this fish jargon, I believe it will do something to the bacteria so they say to NOT use prime so I am using the betta dechlorinator – is that unheard of to read almost 1ppm in tap water?
My PH is very high in my water at around 8.2… no nitrites or nitrates. Is that PH much too high?

I am a little confused because your posts are all very clear to me and the way I am interpreting what you say is to keep it ABOVE 7 PH to cycle your tank so 8.2 should be good correct? The Fluval page and other threads I have read about using the beneficial bacteria say anything above 7 will release the toxic gaseous parts of the ammonia so always keep at for right around 7… Could you also clarify this?

Thanks so much!

Hi Dominique,

My apologies, My internet has been down for the last few days and I am only just getting around to answering the backlog of questions – don’t worry, I’m not ignoring you 🙂

I personally recommend TSS because it’s the same stuff as Dr Tims one and only. Now, there is a lot of debate about this, but DR Tim discovered that not all strains of beneficial bacteria are the same. He used to work for Tetra before breaking off and doing his own thing. Many of his discoveries have pushed the hobby forward. These two brands of products are considered to be the only strain that actually helps in an aquarium cycle. It’s still very much a YMMV kinda thing, but anecdotally, I have seen a lot more success with these two brands than the others.

I personally would have avoided using the aquarium salt, but I would trust what the folks are saying on thread. If that’s the advice they are giving, then it’s worth a shot.

As for the ammonia reading, it isn’t unheard of. Most water supplies now use chloramina instead of chlorine, since it stays in the water longer. chloramine is a mixture of ammonia and chorline. So when you break the bond, ammonia is then readable.

Hey Ian!

So I have been so caught up with a death in the family and the hurricane we just had that I am scared I totally screwed up. I hope this is an easy one and I don’t blow your mind again lol.

It has been over 14 days since I added the TSS to my 5 gallon with tank with my half moon Champ. This was the tank that I was doing fish in cycling using prime however after 3 weeks over 0-.25 ammo and nothing else I added a bottle of TSS. After a few days my ammo was .25 0 nitrites and between 5-10 nitrates and stayed that way during the last 2 weeks.

The ammonia would fluctuate between 0-.25 NEVER showed nitrites which you said could be normal because of the way my tank was cycling and nitrates were ranging from 5-10. Now rewind to the day after I added the TSS – I totally forgot about not being able to add prime and reading back in my journal I did dose 1ml of prime because I detected .25 ammo so I am hoping I didn’t ruin it then.

However fast forward today about 20-23 days after adding the TSS and nothing else champ went into his cave that I have in there and hasn’t come out all day. He hasn’t done this since I first got him and I think that was from depression but since he has been in there all day I tested the water and got .50 ammo, .25 nitrites and 10 nitrates.

Now my most important question is did I ruin the cycle since I didn’t do the water change after 14 days?

Also important question/concern the entire time I have had this tank going which is about 3 months I’ve never detected nitrites. However today is the first time- could that be because I am over 14 days without a water change?

I know that you won’t get this for a little while and don’t expect to be first on your reply list lol so I am going to do A water change. I am getting .50 ammo and .25 nitrites so does that mean I need to do 10-15% water change? I was thinking maybe a gallon to 2 gallons since it’s a 5…..

Also do I need to dose the water with prime and let it sit over night? I have been adding it after about 1hr however I just read on another forum you always have to let your water sit 24hrs after adding dechlorinator not because of TSS just always something you need to do!

Also, is there anything else I need to do besides the water change and add prime?? I’m scared to do this because part of me is wondering if I’m just half way through the cycle now since nitrites are just appearing and ammo is the highest it’s been at .50….

I think I might put him in a 1 gallon tank with conditioned water until I hear back because i don’t want to ruin anything lol. Thanks in advance Ian!

Hi Dominique,

This tank has a filter in it, right? I tried looking for the previous comment where you described the setup but I couldn’t find it (I may have missed it, there were a lot to go through :P)

It sounds like this tank may still be cycling, just super slowly. Fish-in cycles are generally slower than a fishless cycle. A member of my local fish club just finished cycling his 200 gallon with a fish-in cycle, it took a little over 4months.

A water change and prime dosage should get thing back on track. But it’s mostly going to testing be managing these parameters regularly to keep your fish safe. Remember, 1 dose of prime treats up to 1ppm of ammonia and nitrite combined.

As for the aging aquarium water, it’s how things used to be done in the old days, we would let water sit so the chlorine would offgas and the temperature would match. These days chloramine is used in water supplies instead of chlorine, which means it is harder to remove from water. These days, chemicals like prime perform the job instead, however many people still choose to age their water. The main benefit of aging (if you are using prime) is that it allows the water temperature to reach the same temperature as in your tank, which will reduce the temperature swings when you add water in your tank. Rapdid temperature swings can cause fish stress.

Hi Ian,

I started an entire new thread with 3 different concerns I have hoping for some advice. I am just now seeing your reply to this and I am glad I did because it’s giving me a date range since I have my notes on water parameters and what I add to each tank pretty unorganized going back and forth in two different planners so I am going to make sure I start a new notebook NOW to have this…. anyways yes this tank had the built-in filter, it was a Top Fin 5 gallon Retreat with an integrated filter. but as you will see in my new comment from today he is now in a different tank…

I have updated readings for you which I didn’t have in my earlier post which I’m sure will help you…

Starting with Sassy- i dosed her with TSS and never showed nitrites this is the tank im talking about in earlier post when I mentioned re dosing with Fluval Bacteria Booster which is a 3 day dosing and yesterday was day 3… her readings are now
0-25ppm ammo (i can never tell exactly the difference between the two i always see yellow but then some angles a hint of greenish-yellow and this is in all forms of light natural and all)
.25 nitrites (for the first time) none were detected after using the TSS
5-10 nitrates. I did about a 50% water change and added dechlorinated water using prime 4 days ago prior to dosing with the Fluval BBB….. assuming its .25 ammo, .25 nitrites, 5ppm nitrates and 8.2 ph (which think is really high) oh lord I hope we can fix this or you tell me it’s looking good because I can’t lose another baby….should I dose with prime since it’s still below 1ppm with nitrites and ammo together or would you say do a water change? the directions aren’t clear on the package of Fluval so I don’t know if I should wait a few weeks like with TSS…. however, I do see much quicker positive readings and of ALL of them where I’ve never gotten nitrites with TSS….

champs tank after waiting a few weeks after dosing with tss and doing about 90% water change due to his fins is reading

ammo- 1ppm (highest ever) my water before adding anything is at .50
nitites- 0
nitrates – 0

i find it very strange the ph is so different between the two tanks since the only thing i did diff was add the Fluval Beneficial Bacteria to Sassys but I dont think that would raise the ph… and i did almost 100% change in champs and didnt add more bacteria but am reading a much higher ammo reading then sassys in which i did add the BB…

This is so frustrating, i feel like an IDIOT for still having issues with the darn cycle.

I guess im going to dose champs with prime for the 1ppm of ammo and wait for your input and see if i can find more info about fluval but i think i should dose with prime just in case for the .50 totall ppms between the ammo and nitrites……

im not sure what to do about the ph

thanks ian,


Hi Dominque,

It can be very helpful to test the pH of your tap water so you know what you are dealing with. This is the base level of pH that your tank should return to with each water change.

For sassy, these are closer to the results I would have expected (nitrates YAY!) Regular water changes and prime dosing should being immediately (ammonia + nitrite = .5) If you do a big water change, the goal is to get pH back to the 6.5 – 7.5 range, which you should be able to.

For Champ prime as well. pH can be affected by substrate and a wide range of things. However, this introduces KH, which I have an article on as well. I typically don’t mention it since most people don’t need to balance it.

Weekly water changes and waiting would be how I would proceed, but I still recommend looking into a fish club as per my other comment!

I would stop with the beneficial bacterial boosters for now.

Can you clarify how getting the ph down by water change is the way to go? My water reads around an 8 out of the tap. I just ordered a shower filter head and nozzle for bathroom. I’m thinking I’ll start using water from there since it’s filtered for my tanks – after it’s installed I’ll get you the readings.

But anyways how can I get the ph down?
Should I do a water change now with her or just dose with prime?
Champ only has ammo and 0 everything else so I dosed with prime and will not to water change until I see the others show up correct?

Is it okay that I added the jungle cure during this process?

Hi Dominique,

If your pH is that high out of the tap, then that’s the level at which it will be increased to during each water change. I have seen plenty of betta live full lives with a pH of 8. It’s fine. You should be trying to keep it constantly at 8 if that’s what comes out of your tap. A weekly 40-50% water change will help keep it it 8. If it drops before the week is out, then you will have to read up on KH, but hopefully it’s not an issue.

You should be doing a weekly water change on champ too during this process.

Hi, I’m 3 weeks into a ‘fish in’ cycle (I was duped into it by a well known pet shop chain ????). I’m doing regular water changes, my 6 Black Phantoms are doing well. My question is this, I have an established cold water tank which houses 2 goldfish, the two filters are different, could I somehow use media from the goldfish tank to help speed up the process in my tropical tank?

Hi Su,

Absolutely, if you have some ceramic rings in the other tank or other filter media that can be removed, and place it in your current filter, it will speed up the cycle.

Hi again Ian,

Since your last reply, I’ve had to do daily water changes just to get nitrates down to 20ppm and I’m not sure how long I can keep this up.

After your reply, I went ahead and did 6 50% water changes (2 hours in between each one) to get it back down to 20ppm, but since then, the number just keeps doubling daily. Example, Friday it was 20ppm, Saturday it rose to 40ppm (before the 50% water change). I had to go out of town for work on Sunday and when I came back today, the nitrate is now 80ppm.

What is causing the nitrates to climb and how do I stabilize it? With an old back injury, it’s increasingly hard for me to keep up with the daily water changes. Please help!

Hi Aimee,

If your tank has cycled, you can stop adding the ammonia. Nitrates will forever climb – it’s the last stage of the cycle and can only be reduced by water changes.

Have you gotten your fish yet? If not, it’s time if your tank has cycled. Ammonia from fish will build up at a much slower rate – you should be able to go for a week between water changes!

Hi Ian,

How do I know if my tank is fully cycled if I’m doing daily water changes to get my nitrate down? I’m not sure but I think the reason nitrite is down to 0 is precisely because of those water changes.

Nitrate is the least harmful to fish but at a level of 80 and above, it can still be toxic to fish, am I right? So if I do add fish at this point, would I still have to do daily water changes to get it down to below 40ppm?

Hi Aimee,

The aim is to get it down under 40 and under 10 for when you have fish (before you add them). If your nitrates are building at such a rapid rate then your tank should be close to cycled if not cycled. Your fish are not going to produce ammonia at the same rate – if you get nitrates down to 5ppm, they might only produce enough to get it back to 20 ppm at the end of the week, a 50% water change gets it back down.

Hi Ian!

Great news, my tank has finally finished cycling after 3 months! Thank you so much for your help and patience. I wouldn’t have been able to do it without your guides and helpful answers!

Anyway, I was just about to buy some new fish when I noticed hydra stuck on my tank walls. Quite alarming to see a lot of them! I managed to get Planaria Zero but have a few questions.

1) Will Planaria Zero harm my new fish (guppies, tetras, algae eaters)? Or should I hold off on getting new fish until I get rid of the hydra?
2) If I do decide to wait, I have to keep dosing ammonia daily to keep the beneficial bacteria alive, am I right?
3) Do I have to remove ceramic rings before adding Planaria Zero?

You advised me a few weeks ago to hold off on adding white coral until my cycle was done. Is it ok to add it now or should I wait until the hydra is gone?

I’m also gutted that I lost my betta fish to dropsy a few days ago 🙁 It was very hard having to watch him succumb to it. The tank was cycled, readings were good and i performed weekly water changes so I have no idea why it happened. Would you have any ideas on how to prevent dropsy? The only thing I can think of is, I fed frozen bloodworms to him about once a week. Can frozen bloodworms cause dropsy? Also, how do I go about cleaning the tank (without destroying the beneficial bacteria) so that the next fish won’t get it?

Thanks Ian!

Hi Aimee,

That’s awesome! Well done for having the patience to cycle your tank!

ohh, hydra are a nuisance. If you are in the unique situation where you have no fish in the tank, my recommendation would be to get rid of the hydra first.

While I have no experience using planaria zero in a cycled tank, my assumption would be that it would be safe to continue adding ammonia. After all, fish are continuing to produce waste during this time which turns into ammonia and no, you won’t have to remove any filter media.

Just make sure you follow the instructions closely. Like with any medication, using it incorrectly can cause more harm than good.

I’d also wait until after the hydra are gone. Just so you can tackle any issues that arise one at a time while being confident of the cause.

I’m so sorry to hear about your betta. It’s very difficult to narrow down what the cause was. Fish show stress very different to us humans (they don’t really show it at all) it’s possible that something went wrong months ago and the illness only just came on. Bloodworms shouldn’t cause dropsy and the good news is that dropsy isn’t considered contagious, so you shouldn’t have to treat the tank.

Hi Henry,

Instant cycle and drastically shorten the cycle do not mean the same thing. I can see how you would find that confusing though.

Hey Ian,

I hope your doing well and hope that I am not wasting your time because I cant imagine how hard it is to work and keep up with a busy blog the way you do! Anyways, I know that I posted a comment about my current situation after telling you about Luna’s death however I literally have looked through each thread of our comments on multiple different blog posts of your and cant find it for the life of me. So, here I am starting a new post and I will keep it to this one to avoid any future confusion

Well, if you recall I have had some confusing, sad, and just plain out crazy issues going all the way back to 7 months ago when I first got my fish. We have been going back and forth since August when I came across your blog, which is a miracle, by the way!

Anyways I have a few sitiations I need help with. I will start with the most basic first. Timmy is my Betta that I have had the longest. He is THRIVING in his 10 gallon tank which I knew nothing about the cycle until about 3 months after getting him. We spoke about this when I first found you and we determined that me having the white diamond zeolite ammo remover in there along with ammo lock had to be producing false readings because for at least 3 weeks i was getting over 8ppm off the chart readings of ammo… Anyways this tank has got to be cycled i mean its been forever and i started over after taking out the zeolite but the way this fish is thriving just tells me something right there…

But… I don’t know why I can’t seem to grasp the concept of the cycle and am having such a hard time.. even with the bi-weekly to monthly water changes, I do with Timmy being in the 10 gallon I NEVER show rising nitrates. If nitrates should be forever rising then that tells me none of my tanks are cycled because his readings are typically always at 0…. the ammo is very hard to tell between 0 and .25(yes I do read in the daylight) but I usually do a water change when i see what I think could be .25 ammo but from your posts and advice to others I think a water change should be done based on the nitrates..

So when should I do the water changes and if i see 0-.25 ammo and have yet to see nitrates rising would you advise dosing with prime? Correct me if I am wrong but the only time I would use prime is when ammo and/or nitrites equal 1ppm or higher so if i test and get above 0-.25 ammo, o nitrites and 0-5 nitrates I would NOT use prime OR do a water change… the only time I do a water change is when nitrates get above 40ppm… if I am showing 0-5 nitrates and for some reason either of the other two get to 1 or above then use prime but no water change….

That brings me to sassy. She is still good after having fell 5 feet from her tank to the floor, her ripped fins are already grown back… what weird with her is she will show signs of bloating or swim bladder for a little while (less than 24hrs) and then go back to normal…. I limited her to 2 pellets a day and go 1 day a week not feeding her since she’s so little but I am not sure what’s up with her lol.. she’s just a weirdo… I don’t know if what I did was okay but since I moved her from a 3-gallon tank with a built in filter to a 3.5 gallon tank with an aqua clear HOB filter.. the smallest one they have is for up to 30 gallons but I have the input blocked with sponge and a big sponge blocking the output to slow down the flow.. anyways shes been in there about 1 month or so and just the other day I decided to re cycle her tank in case I missed something..

What I mean by that is that I did about a 50+ water change and added fluval BBB… it’s only 3 days worth of dosing for a new tank so yesterday was my last dose so im going to take her readings again… now if i get high nitrates does that mean large water change even if ammo and nitrates are at 0?

Okay now on to Champ… this is the sitation I know I left a post about but cant find anywhere… he is a half moon better that I rescued because he literally looked at me with those big eyes saying please save me lol.. anyways he has a little tumor on his left side which i noticed the day I got him, i dont even know if its in fact a tumor but its been there since day 1 and doesnt seem to cause him any pain or issues…

I had champ in a 5 gallon tank that also had a built in filter.. i hate those built in filters because the chambers are SO small they have no room to change out the pads for anything else, this was the tank you tried walking me through cycling… hit went about 3 weeks with no signs of ammo at all… then finally after dosing with tss i thought i had it cycled but i kept seeing green algae on his decorations and have never ever had algae in any tank… His fins were literally in a perfect D shape with no tears, and not one spot that was out of place, they were so perfect it looked like someone cut them to perfection… well right before switching his tank I noticed some fin rot or maybe tearing so I moved him to a bowl with a heater and treated with salt for a few days… he seemed so sad though so after 3 days I put him in his new 10 gallon – aqua clear filter, only silk plants, gravel, a shell that is made of glass and very smooth and a cave with no sharp edges… He has never been exposed to bad water parameters however his fins are getting worse by the day. I don’t know if he’s biting them, tearing them or its actual fin rot. Champ is a steel gray/bluish color with black on the top of his head and red/black in his fins so I can’t say if its rot or not.. all I know is they are getting more jagged and uneven by the day… I just did almost 100% water change and dosed with prime and salt but they arent getting better…

I watched so many youtube videos and by the majority of things i read i decided against bettafix/pimafix/melafix which I have used on my others but from the comments about it being hard on their gills and breathing im not going that route…

I read alot about jungle fungus clear and kanaplex so I ordered that on amazon.. i recieved the jungle fungus tablets but the video i watched shows to use both together so im waiting on the kanaplex..

now, the only thing that comes to mind if the fact i took him from the 5 gallon with the built in filter which had barely any movement from the flow to the 10 gallon with the hob aqua clear, it does have the switch to change the flow to lighter but its still much more then he was used too…. I put a sponge that i use for the mechanical filtration blocking the water but I dont know if that would have caused the tearing or fin damage…

I dont know what else to do… Even if its tearing I would think I could treat it the same way as rot to PREVENT rot… I know less is more thats why I was leaving it alone with the one time dose of aquarium salt but thats not working! and i know I need to do something because its getting worse by the day

Other then that he seems to love his tank, he swims all around, he’s eating fine… if anything his appetite is growing, he always comes to the front of the tank to flutter and greet me so he isnt showing signs of sadness or illness.. I wish I could upload some photos but I dont have the option here…

…. I know that was a lot of information to cover in one post so hopefully, I didn’t repeat myself or confuse you, I almost confused myself there for a second lol… but I will wait to hear back from you… short recap

1. how do I know if my tanks ever fully cycled and if not what do I do to restart this process?

2. if we decide to recycle would you suggest the in fish cycle with prime and not add anymore BB even though I just added it last month when switching sassy to her new tank and AGAIN in her tank 3 days ago? I also added it to champs new tank on 10/12, never saw any ammo or nitrites but saw around 10 nitrates on the 25th… I did a 90% water change on his tank only because of his fins so im not sure what to do.

3 Since Sassy’s tank was dosed with TSS around 9/16 when setting up her new tank could I have hurt her by adding the Fluval BB dosage for a new tank the other day.. I don’t even know why I did this…

4. Timmy has been here for about 6-8 months and since I don’t think I ever cycled it right would you suggest adding BB or just not changing the water until I see nitrates since they have yet to rise?

5. Is there such a thing as over cycling? Since I am using the aqua clear HOB filter that says UP TO 30 gallons on a 3.5 and 10 would this maybe be hurting it?


Thanks so much

Hi Dominique,

I looked through all your other comments but I replied to each one. I’m not sure what happened to the one that has gone missing.

Bare with me as this is a long post with a lot to take in. I hope I answer everything, please let me know if I didn’t.

Your 10 gallon tank is very likely cycled. I’m not sure what is happening here. If I was in your situation, I would order a second nitrate test kit, just to confirm (I don’t remember if you have double checked your test) but for it to be up for 3 months, unless something is amiss, if you have your filter set up with sponge and biomedia, and you have not missed anything, then I don’t see how this tank couldn’t be on it’s way to being cycled.

I am at a loss why the cycle is such a challenge for you. But don’t stress, I am confident we will get there in the end.

I would not advise restarting the cycling process. It is unlikely that something in your tank is killing beneficial bacteria. If your test kits read zero for ammonia and nitrite then that is the most important thing. For Timmy’s tank I would suggest just doing weekly water changes as normal, testing as normal and unless you see ammonia .5 or nitrite, I wouldn’t stress.

There isn’t such a thing as over cycling. You can use the largest filter you can find. If anything, these are better since they can hold more beneficial bacteria – you can never have enough of these.

With champ, it’s hard to say. It’s possible he is just a sick fish. While some fish have tumors for life, and still live a full life, for others, it can be a sign that the fish is unhealthy. It’s possible that champ is sick and that has caused these other health issues to arise, despite you doing everything right. If you google pictures of fin rot, you should be able to determine if that is the cause. Finrot is typically caused by poor water. If it is tearing, it could be decorations or any number of causes. The cure for both is time and good water quality. Again, even if you do do everything right, due to champs health issues, it might be that he is on the way out.

Dosing the tank with Fluval BB wouldn’t have hurt her. Bacterial boosters don’t harm fish, but they may not help your cycle speed up either.

On the water change, you don’t change according to nitrates, you would do a change each week (ideally) as there are trace minerals that fish draw from the water that need replenishing. A weekly water change also keeps water as fresh as possible and gives a regular test period for you to catch any issues before they get too serious.

Oh, I should have asked, do you have a local fish club near you? These are groups that meet weekly/monthly and are a wealth of knowledge on keeping fish. It is generally an older crowd, I am unsure of your age but you may need to ask a parent to go with you if you are younger. If you google “local fish club” or look for facebook groups, you might be able to find one near you. These are great because these people use the same water source as you and can identify any hurdles you need to overcome. Alternatively, I do recommend joining a forum or facebook group to post your questions to as well – it’s possible that someone might catch something we have both missed! I’m not saying this to get rid of you, I’ll still be here to help. I just want you to get through these problems as quick as possible, so you can enjoy keeping fish without issues!

Thanks a lot Ian. I used the prime dosing method in champs tank and sassys since both their parameters rose after doing large water changes . Champ had 1ppm ammo which is the most ever: I used 10 drops of prime. Sassy has .25 ammo .25 nitrites and 5-10ppm nitrates.

I changed a little more of her water last night and added in jungle cure which claims to be good for fin rot, swim bladder, internal damage and more. Last night she couldn’t move- she was floating on her side and now she’s swimming great.

I think I’m going to use it on champ what do you think?

I also have a minor issue with Timmy’s tank all of a sudden showing brown sludge on the walls , decorations and plants. I read This is not algae rather a microscopic organism called diomox (I spelled that way off) but they said this is normal in an aged tank and it’s actually not bad for the fish at all.

I do wipe it down everyday because I don’t want it to get out of hand but what causes this and is there a way to stop it?

Thanks Ian

Hi Dominique,

Those readings look considerably better! I have my fingers crossed this is the start of the cycle moving forward.

For Champ, It couldn’t hurt, but again, it might not help him.

On Timmy’s tank, this is likely diatoms. While it may not be algae, it’s commonly called “brown algae” – it can be wiped down and if all your parameters are normal, it often goes away on it’s own. It’s particularity common in newly cycled tanks.

Thanks Ian,

So for a little update after dosing with prime and using jungle cure and kanaflex on sassy and champ I just did a reading so within just 24hrs

sassy tank is
went from 0-.25 ammo to ZERO, the nitrites were spot on to the lavender color for.25 on the master test kit but now their much lighter their still above 0 but under .25 and shes still now showing slim to no nitrates,,,, . ( i wonder what I did to lower the nitrites this is good to know for future reference. All I can think of is 15-20% water change … her paranters seems good, except that the nitrates have gone down

now champ is only showing ammo which I did lower from 1ppm to about .25 ammo, 0 nitrites and 0-5 nitrates,

since I am sort of re doing a fish in cycle for the what feels like 100th time in less then 8 months I wnat o make sure I do it right for once,
Should i be dosing with prime every single day or only when the parameters get to a certain number? im doing prime vs daily water changes so at what point do i need to change my water?

by the way i wipes down timmys tank every day along with decorations since I have noticed this but keeps coming back. its not like bombarding the tank though. I read somewhere that fish won’t die from this instead some could thrive…

would you suggest almond leaves for sassy and champ issues or finish the jungle cure and other medication 1st?

Hi Dominique,

A water change will lower the nitrates, so if they increase again, do nothing but a water change and see what level they drop to.

Ideally you would dose prime every day since you won’t be testing hourly. It’s possible that ammonia and nitrite could reach a combined .5 and you are not there for many hours, during this time it could stress your fish.

Brown algae (diatoms) are harmless. I would take a step back and let it run it’s course – see what it does after a few weeks. Unfortunately, brown algae is often a wait and see game.

Generally speaking, with medication, once you start you should always finish the course. You can always add indian almond leaves after.

Hi Ian,

Happy Thanksgiving! I hope you had a relaxing and wonderful day!

Well, I’m back again with an update and a new tank now LOL…

So… I tested Champs water on 11/17 and ammo: .50 / nitrites 0 / nitrates around 2.5 / PH 7.6…..on Wednesday 11/20 I did a 75% water change in his tank since I was done dosing with all the meds I was using and cleaned out his filter – I have the aqua clear so the sponge goes on the bottom, then charcoal in the middle (which I don’t use) and bio rings up top…

BTW champ is a very active and healthy fish besides the little tiny lump that he had when I got him and the tears in his fins he is an active, playful fish, does alot of swimming, and never showed any signs of behavior or mood changes

I put in a new sponge on the bottom, left the old one on top, added the charcoal and zero carb packet in between and then the bio rings that have been there back on top…I also added the recommended maintenance dose of Fluval Beneficial Bacteria to his tank for water changes.

Today 11/28 here are the readings for my tanks.
Ammo: .50 ppm
Nitrite: .25 ppm (not sure where the nitrites are coming from unless I restarted the cycle)
Nitrates: 2.5ppm
PH: 6.0 (this is the lowest ever! My natural ph in my water is around 8 and none of my tanks have ever gone below 6.8-7.4)

regarding his PH should I let it run its course, I dosed with prime according to the ammo and nitrites but haven’t done anything to raise the PH yet…

Ammo: 0
Nitrite: 0
Nitrate: 0
PH 6.6

(this is the tank that HAS to be cycled its been over 6 months but I still am never getting rising nitrates)

20-gallon Sorority Tank
My friend had to move out of town last minute and I couldn’t let her kill the fish so I now have a 20 gallon with 3 neon tetras, 2 Mollys and I think 2 platys. The tank was in bad shape so I had to restart the cycle and ended up losing a few along the way…

I lost a danio, neon tetra, dwarf gourami and a molly…. the 7 in the tank now seem to be great and getting along, they were bullying the gourami even though he was the biggest fish i was surprised to see my little orange on with the mickey mouse on his tale and a few other nipping at him all day long bullying him. A few times I thought he was dead but then he would move slowly and lay back down… I am not sure if its the in fish cycle that killed him or they did LOL…

I started on 11/20 and I used TSS to get the cycle going…..
I dosed the tank with API general cure and jungle fungus… I did NOT do a water change as recommended after the last dose because I am still cycling.

Anyways, I am clearly forced to do this in fish cycle. and using prime…..

Today 11/28 my readings are
ammo: 1ppm
nitrites: 0
nitrates: 2.5
PH: 7.4

dosed with 4ml of prime – I am not going a water change until my ammo gets to 2ppm or my ammo and nitrites get to 4ppm together right?

Sassy isn’t doing well… I have treated her with many antibiotics bacterial – parasitic – Kanaflex, etc and she’s holding on but she hides all day and comes out once every other day to see me but she’s fighting for her life I guess I have to euthanize her using the clove oil which is really sad for me!

Any suggestions on Champs readings? And the new 20 gallons? I am correct that I keep using prime and don’t do any water changes until ammo gets to 2ppm or higher and ammo + nitrites 4ppm for above correct?

Thanks Ian!

I meant I added ZEO CARB to champs tank….. that’s a mix of the white diamond ammo neutralizer and charcoal – im wondering if I should take that out…. I’m not recycling (on purpose at least LOL) so is it ok to leave?

Hey Ian,

One last thing I wanted to mention.. I just replaced my shower head with two parts an actual filter that attaches to the showerhead and a filtered head. It feels amazing I can smell and feel the difference. It is a 15 stage shower filter that claims to soften hard water – remove chlorine, fluoride, lead, heavy metals, bacteria, pesticides, chloramine, ammonia smell, sulfur, and other sediments

I just tested the water right now and my readings are
Ammo: 1ppm
Nitrates: 0
PH: 7.6
KH: 75-150
GH: 120

now- im assuming the 1ppm ammonia is probably ammonium because the showerhead doesn’t say it filters that out… are your thoughts the same? It does cmalim to soften hard water and the KH seems to be higher then my tap water HOWEVER i am using the tetra strips and i lost the cap so there has been no cap on it (im not sure if that makes a difference)

im just trying to figure out why champs PH is SO low.. its a 6.0
my PH has always been between a 7.6 and 8.0 in my tap water and now its a strong 7.6 with the filter so do you know what could cause it to drop so much and how i can raise it? I know that 6.0 is bad especially since hes still cycling.

And what do you think about the 1ppm ammo reading? If I am doing water changes and putting water back into the tank with a higher ammo reading then i have now then wont that hurt them?

Thanks Ian!

Hi Dominique,

Sorry for the delayed reply, I was hosting the family for thanksgiving and it was a full time job!

Firstly, that sounds like an awesome showerhead. You are not using it for your aquariums are you? The soft water can cause issues, which can lead to pH fluctuations. Aquarium water needs some KH and GH (hardness) in order to keep healthy fish. Prime treats tap water just fine. The shower head sounds great for you but probably is not the best thing for your fish. On the strips, if you lose the cap, they can absorb moisture which can result in incorrect readings.

For champs tank, doing a water change should be all that’s needed to get the pH back up to an ordinary level. I wouldn’t take a wait and see approach here, you should see immediate improvement since your tap water is a higher pH and KH.

I’m unsure what’s the go with Timmy’s tank. I have never seen a tank not show nitrates at this stage unless they were being removed in some way. If you are sure you are testing properly then just keep doing water changes as usual.

I’m sorry to hear about. From what you were saying before, I kinda thought this was the direction things were going in (although I hoped she would turn around)

On the sorority tank. Good on you for trying to do the best you can for these fish! It sounds like they have had a rough life. Hopefully you can save some of them!

If you are doing the prime method, you only need to water change when ammonia or nitrites + ammonia reach 4 ppm. However, if possible, it is best to do it more frequently if your schedule will allow it.

I have done a water test today and based on the PH readings I did a KH and GH reading as well but I am not going to post the results for the KH and GH until I can either find clarification online or from you however the directions confused me very much…

Champs PH was very low last week 6.0 but I used alkaline buffer and tested the day after and it was 6.8 now its a 7.2 but after doing timmy’s water change his is very low (6.0) luna’s is 6.0 and my other bettas is 6.8 which I havent done any water changes in so once I am able to clarify how to read to KH and GH test maybe we will know better…

1. Fill the test tube with 5ml of tank water.
2. Hold the bottle vertical and add KH solution ONE drop at a time, be sure to add the number of drops being added.
3. Cap and invert test tube several times after each drop
4. THE TEST IS COMPLETED when the water in the tube, after haven been shaken, turns from blue to yellow.
5. The KH value is determined by the number of drops that must be added to turn the water in the tube bright yellow…

Per the directions it only takes 1 drop for each tank to turn from blue to yellow so it says that would be the end of the test but continuing on to step 5 it says I determine the KH value by how many drops it would take to get it BRIGHT yellow which would be MUCH more than 1 drop….

Anyways the test are

Ammo: 0
Nitrite: 0
Nitrate: 0
PH: 6.0

Timmy (tank ive had almost 8 months)
Ammo: .50
nitrite. 0
nitrate 0
ph 6.0

ammo. 1.0
nitrite 0
nitrate 0
ph 7.2

Bella (new tank I am cycling for a few weeks)
ammo 0
nitrite 0 (28th it was around 3.5 – 30th got down to .75 now its 0)
nitrate 0
ph: 6.8

20 gallon
Ammo. 1.0
Nitritre: 0
Nitrate: 0
PH 7.6

My tap water does read 1.0 before I add anything to it straight out of the faucet so could that be why I am getting readings in 3 of 5 of the tanks or should it be showing zero after a week or so from the water change? Its so weird none of the tanks are showing nitrates… I am getting very frustrated!

Hi Dominique,

Unfortunately, on the nitrate front, I highly recommend contacting your local fish store (not a big box chain like petsmart or petco) or your local aquarium club for help. Unfortunately, it doesn’t seem like this is an issue we can diagnose online (it feels like we have tried everything by now.

Hi Ian!

I went back to my history tab in my settings to make sure this was where I remember posting my comment on 12/9 and it’s showing the comment (awaiting moderation) however when I come directly to your site the comment seems to have not come through so I copy and posting it again…

Anyways no problem at all for the day or two later reply – I never expect such a fast response, especially on a holiday.
I want to start by saying thank you for being here for me through this crazy process I have had!

Since I am updating my comment I have to change this part unfortunately… when I wrote it as of the 9th Sassy made a major turn around. I was going to go through with euthanizing her on Thanksgiving but having found one more option I decided to use another round of API fin and body, API general cure and do Methalyane Blue dips which I have also been doing for champs fin rot since NOTHING has worked on growing his fins back….

From 11/30-just a few days ago (so just about 2 weeks) sassy showed no signs of sickness. Usually, she would be ok for a little while then she would go back to laying on her side and looking so sickly… Just up until about 2-3 days ago she was swimming around, not hiding in her castle, and i didn’t see her go on her side ONCE… well now shes doing it again.. not as bad but my hopes arenas high…

My local GNC has clove oil back in stock so im going to buy some and have to make a very hard decision. I dont know why i cant just do it but I really cant 🙁

Now i already know what your thoughts are on her ever since I told you about her fall so I guess my questions about what you think of MB would be more directed to champ..… He has NO signs of sickness, no breathing problems, no hiding, no appetite suppressant, ONLY torn fins. His are VERY noticeable being that he is a moon tail and his fins were shaped in a perfectly even D shape- they were so perfect I remember saying it looked like someone cut them that way but now they are all torn, uneven and rigid… I can’t tell if there are black tips because he is a stell blue color with some sort of marbling on the top of his body which is black and his fins go from blue to red and black anyway so I don’t know if its actual fin rot or just torn/ bitten fins but either way they won’t grow back! Right now I have had Sassy in a small hospital 1-gallon tank with MB since I saw her reverse back BUT I’m thinking no more options with her… There is so much info online so would you suggest giving champ 10-second dips with salt twice daily or more like 30 minutes or do you have a better idea?

Champ has never been exposed to bad water parameters, however for some reason for the first time after doing a water change I am getting a reading of 1ppm ammo (which has always been at 0 so I have NO idea why it is reading one now but I treated with prime and can only think that since my regular water has 1ppm right from the tap maybe im always going to get a 1ppm reading (however I don’t have that in every tank….

Since this post is technically from 4 days ago I am going to test all 5 tanks – post the results and direct my questions about kh to your KH post!!

Ill be back in a few hours with questions about my water tests and KH… thank you in advance for all your help with this post for now

Hi Again Dominique,

I am unsure as to whether or not MB would help champ as it entirely depends on what the cause is. If it’s physical, then adding chemicals isn’t going to solve the problems. If you have 1ppm of ammonia in your water then it’s possible that this is the cause of it’s appearance in his tank. However, this should have disappeared by now if the tank is properly cycled (the beneficial bacteria will catch up to it)

P.s I’m really sorry to hear about Sassy.

I’m new to the hobby. I’ve only ever had betta fish in a 5 gallon tank. I recently bought a 29 gallon tank. I’m confused about the cycling process and worried about the fish I bought. I’ve had the tank running since November 28th with a used filter from my sisters established tank and treated the water with conditioner and added bacteria aqueon balls. The ammonia spiked and dropped to 0 the nitrites and nitrates never spiked. Does that mean the tank is not safely cycled yet? 4 days ago i bought two neon tetra fish. I test the water everyday and the ammonia, nitrites, and nitrates continue to be zero. Is this good or bad? If my tank is not finished cycling how do I keep my fish alive until the cycle is over? Any advice would be great! Thanks!

Hello Ian

I have a question about ammonia. I detect about 1ppm ammonia in my tap water before adding anything to it… I was thinking that in a cycled aquarium even though its showing 1ppm it would eat that up and after 1-2 days I would be able to get a zero reading.

However, for some reason now during all of my water changes I am showing 1ppm ammo… I just did my water change for Timmy’s tank (ill-use him for example since I have had him almost 1 year now and have always gotten a 0 reading for ammo)

readings are
ammo: 1ppm
nitrite: 0
nitrate: a little above 0
ph: 7.0

Hi Dominique,

You are correct, if you are reading 1ppm of ammonia after 1-2 days then there is likely a cycling issue.

Hi Ian,

I had a tank that sprung a leak at the top so I bought a new tank and didn’t cycle it before adding my fish. 🙁 They are alive and my ammonia has been at 0.25 ppm for three days. I still have the gravel from my old aquarium, but it hasn’t been wet in about 3 days. Would it still be beneficial to put that gravel into my new tank to help speed up the process? I also moved the existing filter over to the new tank so hopefully that helps.


Hi Maddie,

After three days it’s likely that adding it won’t have an impact, since the bacteria need to remain wet. Unless you planned to use it anyway, I don’t see a benefit in adding it.

Hello! I’ve got a 10 gallon tank that is overcrowded and I’m in the process of setting up a 20 gallon tank, but it’s not cylcled yet. I’ve been doing 20% water changes daily (just water I’m leaving the gravel alone) to drop the amount of nitrites in my aquarium, because that’s the only test my tanks failing. The fish seem fine and are all still active, but until the new tanks ready how long can I keep up the water changes? Furthermore, I’ve noticed a green algae forming on the aquarium glass and plants….. will this algae harm my fish?

Hi Keli,

Generally speaking green algae is harmless. It’s likely green spot or green dust, which you can read about more in my guides in the algae section.

On the water front, you can do daily water changes as often as you want, and in a crowded tank, you may need to do so daily or more. The idea here is that you want to keep your fish safe from ammonia and nitrite, so if you see these raising within a day, then you’ll want to do water changes to get it back down. Remember: a 50% water change roughly drops these levels by 50%. And to make sure you are reading the levels right, don’t forget to check the results in natural daylight. Indoor lighting can make the colors look off, which may lead to you doing water changes when you don’t need to.

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