Last update: November 15, 2023

Ceramic Rings: Affordable and Effective Bio Media

Note: While this guide focuses on ceramic rings, the information is relevant to any ceramic-based aquarium filter media.

You know those white colored beads…

The ones that sit inside aquarium filters?

Well, those are actually ceramic rings.

And when used properly, ceramic rings provide powerful biological filtration for your aquarium – keeping your tank safe from dangerous chemicals!

Today, I’m going to teach you all about them.

What are ceramic rings?

Different types of ceramic rings used in aquarium filters

Sometimes referred to as bio rings, ceramic rings are unglazed pieces of fired ceramic. Most commonly, they resemble small white beads. However, they can also be found in other colors like cream, gray or brown.

Ceramic rings are designed to have an outer part that has lots of small holes, or pores, and a central hole that goes through the entire thing. This way, water not only runs over the ceramic rings but through them as well.

You might sometimes hear ceramic rings referred to as ceramic noodles because they closely resemble ditalini, a pasta with the same shape. Check it out…

Pasta compared to ceramic rings used in aquarium

The left one is for eating. The one on the right? Shove it in your filter!

Confusingly, the phrase ceramic rings is often used to describe any ceramic-based filter media, regardless of the shape – round, square, even those without holes!

What are ceramic rings used for in your aquarium?

If you think back to the nitrogen cycle, you will remember just how important nitrifying bacteria are.

This beneficial bacteria removes ammonia and nitrites (harmful chemicals) from your aquarium. These chemicals naturally build up inside your aquarium, and if the bacteria in your tank don’t remove them, then your fish will eventually die. As you see, these beneficial bacteria are pretty important.

Well, these bacteria need a place to live. Ceramic rings offer the perfect home for the beneficial bacteria in your aquarium.

You see, beneficial bacteria need a surface to cling to. The more surface that is available, the more bacteria that your filter media can hold.

Ceramic rings increase their surface area through tiny little pores. These pores are so small that you can hardly see them without a microscope…

Microscopic view of pores on ceramic where beneficial bacteria live

It’s in these pores that the beneficial bacteria make their home.

Important: Ceramic rings do not filter your water. It’s the beneficial bacteria that live in these rings that do the filtering. Any new ceramic rings you add to your tank will not have any bacteria on them. Properly cycling your tank will encourage beneficial bacteria to grow on your ceramic rings.

However, ceramic rings have an additional advantage over other types of filter media…

Ceramic rings can hold a second beneficial bacteria:

Denitrifying bacteria.

These bacteria eat nitrates and will only survive where there is no oxygen present.

Denitrifying bacteria live deep inside rock, ceramic and other porous materials, where oxygen cannot reach them. You won’t find this bacteria in plastic or foam filter media.

However, just because denitrifying bacteria help to combat nitrates, it doesn’t mean that you can skip water changes.

How do you add ceramic rings to your aquarium?

Ceramic rings sitting inside HOB filter on back of aquarium

Using ceramic rings couldn’t be easier! Simply add them to your aquarium filter.

Many filter kits already include ceramic rings in the box. If your filter didn’t come with any ceramic rings, or you want to purchase more, their are plenty that can be found online, like on Amazon or from your local fish store – they are very affordable.

While some ceramic rings come with their own filter media bag, others come loose. It makes no difference in performance if you choose to bag your ceramic rings or not.

I personally use a filter media bag since it makes it easier to remove the ceramic rings all at once, especially during cleaning.

Ceramic rings in nylon mesh filter media bag

The first thing you want to do is rinse the rings in de-chlorinated water. Doing so will remove any dust that built up from the ceramic rings rubbing together in the packaging. If you skip this step, the dust could cloud up your tank.

Next, you want to add the ceramic rings to your filter. And, the location is important!

You want your ceramic rings to sit after your mechanical filtration. Sponges, foam, filter floss, etc. should be the first thing that water passes through on its journey through your aquarium filter.

By placing mechanical filtration first, it catches any large particles such as fish poop, dead leaves and uneaten food, preventing your ceramic rings from gunking up.

Similarly, any chemical filtration, such as activated carbon or zeolite should be placed after your ceramic rings.

Important: Ceramic rings need to be kept submerged underwater at all times. The bacteria that live on the rings cannot survive out of water.

How many ceramic rings do I need for my aquarium?

A pile of ceramic rings ready to be used as bio media in aquarium filter

This is a surprisingly common question that I am asked.

Unfortunately, there is no set number – it all depends on the size of your aquarium.

The best answer I can give is…

As many as you can fit in your aquarium filter.

Filters are rated according to the size of your fish tank. Assuming you chose an appropriate aquarium, it should be able to fit all the ceramic rings you needed for good biological filtration.

If you have room to add more, then do it!

How do you clean ceramic rings?

Ceramic rings being used as filter media sitting inside aquarium filter

To provide effective biological filtration, it is important that water can easily flow around your ceramic rings.

Over time, you may notice that your ceramic rings begin to trap waste and restrict the flow of water through your filter.

If water cannot easily flow over your ceramic rings, then the beneficial bacteria that call them home are not going to be able to remove the nasty chemicals that are building up in your tank.

Fortunately, ceramic rings are super easy to clean.

The next time you perform a water change, add your ceramic rings to your bucket of siphoned tank water. Gently swish the water around to remove excess gunk.

It is important to note that you are trying to remove any excess waste that prevents water from flowing through them.

You are not trying to return your ceramic rings to the crisp, white color they were when you first bought them. If you do that, then you would remove the beneficial bacteria.

Your ceramic rings will still look ‘dirty’ once you finish, especially if they have been in your tank for quite some time.

Remember: Your ceramic rings are home to beneficial bacteria. These are living things! If you kill them, then your tank will need to be cycled again. Be careful and don’t expose them to soap, chlorinated tap water or scrubbing.

If you cannot clean your ceramic rings, then it might be time to replace them…

How often should I replace ceramic rings?

Filter media bag with ceramic rings falling out

Exactly how often you should swap out your ceramic rings is the cause of much debate.

Even the manufacturers don’t agree!

Fluval, for example, recommends that ceramic rings be swapped out every 6 months.[1]

Marineland, another ceramic filter manufacturer, states that the rings should never be replaced.[2]

My opinion?

I sit somewhere between the two.

You see, your ceramic rings will eventually wear down. This is due to both the water constantly flowing over them and the ceramic rings rubbing against one another.

As I touched upon earlier in this guide, your beneficial bacteria need rough surfaces to cling to. And if your ceramic rings become smooth, then less beneficial bacteria can to cling to them and break down the harmful chemicals.

Now, don’t get me wrong. This entire process takes many, many years. One of my tanks has had the same ceramic rings (these ones to be precise) for nearly 3 years now, and my aquarium test kit reveals that my biological filtration is as good as ever.

So unless your ceramic rings have worn down or are breaking into pieces, there really isn’t any need to replace them on a regular basis.

If you need to replace the ceramic rings in your aquarium, then make sure you do it properly. Incorrectly replacing your ceramic rings could kill everything in your aquarium, which brings me to my next point…

How do I replace ceramic rings?

Hand holding ceramic rings filter media used in aquariums

If you don’t take away anything else from this article, remember this:

Your ceramic rings are home to beneficial bacteria.

Yes, I know I keep repeating it, but it’s important!

You see… Your new ceramic rings will not have any beneficial bacteria living on them.

Now, this presents a bit of an issue. If you remove all your old ceramic rings and replace them with new ones, you would also remove most of the beneficial bacteria in your aquarium.

And without these beneficial bacteria, you will experience ammonia spikes, which can kill your fish.

So, the trick to changing out your ceramic rings?

Do it slowly!

Don’t remove all your ceramic rings at once. Take out half of your old ceramic rings and add half of the new ones.

This is why I like to use filter media bags. They keep your old ceramic rings and new ones separate.

What this does is encourage the bacteria to grow on your new filter media. This process is referred to as seasoning.

Leave the ceramic rings for two to three weeks before removing the remaining old ceramic rings and adding the rest of the new ones.

Make sure to keep an eye on your ammonia and nitrate levels throughout the entire process to ensure everything is going smoothly. An accurate aquarium test kit is your best friend in this situation.

You can also use this method to speed up the cycling process.

You see, ceramic rings in an established tank, meaning one that has already been cycled, will already be coated in beneficial bacteria. By adding these ceramic rings to a newly set-up aquarium, you can shorten the time it takes to cycle your tank.

Can I use ceramic rings inside my display tank?

While it’s not common, you don’t need to place the ceramic rings inside your filter to receive their benefits.

You see, established beneficial bacteria will begin to colonize your ceramic rings even if they sit in the main tank area.

With that said, beneficial bacteria still need a constant flow of oxygen and nutrients to live.

So if you want to go down this road, it’s a good idea to place your ceramic rings where they will have good water flow – such as directly under the outflow on your filter.

With that said, I don’t recommend using ceramic rings in your display tank. Without the mechanical filtration before them, they will clog much quicker.

What are the alternatives to ceramic rings?

Alternative filter media to ceramic rings

Ceramic rings don’t filter your aquarium. They simply provide a home for the bacteria that do all the hard work.

While there are other types of ceramic-based filter media, ranging from spheres to sticks, they all behave similarly to ceramic rings.

With that said, there are three other types of filter media that you can also use for biological filtration…

1. Bio balls

Pile of bio balls used as aquarium filter media

As the name suggests, bio balls are round pieces of plastic. These plastic balls have been designed to provide beneficial bacteria with many different nooks and crannies to call home.

Bio balls are typically used in larger tanks, refugiums and ponds, providing a cheaper alternative to ceramic rings.

Want more info? Check out our bio balls guide!

2. Sera siporax

Siporax sintered glass biological filter media

Sera siporax, which are very similar to ceramic rings but made from sintered glass, are small glass fragments that are heated and pressed together, leaving plenty of room for beneficial bacteria.

Siporax has about the same capacity for anaerobic bacteria as ceramic rings. However, my personal experience is that it wears down slower and is much less prone to breaking.

3. Lava rock

Lava rock used as filter media in aquariums

A natural porous alternative to ceramic rings.

Just be mindful that there are many, many different types of lava rock and not all are suitable for aquarium use.

You can either crush it up and put it in your filter bag or use it as a decoration in your main tank. Care should be taken if you use lava rock in your display tank because delicate fins can get snagged and scrapped.

Can I use ceramic rings in a saltwater aquarium?

Yes, you can. In fact, ceramic rings’ ability to hold denitrifying bacteria makes it a tempting option.

Despite this, ceramic rings are not commonly used in marine and reef tanks.

This is because saltwater aquariums have the ability to use live rock – which has much more room for denitrifying bacteria to grow.

Ceramic rings just can’t compete.

Any space in a saltwater tank dedicated to ceramic rings would be better filled with live rock!


Ceramic rings are one of the most popular methods of providing biological filtration to freshwater tanks.

Every tank needs biological filtration and ceramic rings are cheap, readily available and long-lasting.

Definitely a winner in my book.

Do you use ceramic rings 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 (69)

Thank you sir. I had so many queries about ceramic rings, and I think I got my answer. Thank you very much sir. I have so many queries also about carbon ( chemical filter ) , please write something about carbon also. Thanks again and good day. ????????

Thank you so much for the article. Very informative. I’m using a lot of ceramic rings for my filtration needs.

There’s one product that I came across the internet. It’s called biohome. It’s made of sintered glass. Would like to ask for your opinion regarding this product. Is the product worth the hype or ceramic rings will do just fine in doing filtration?

Hi Wendell,

I have no experience with Biohome but I currently use Sera Siporax in my tanks and have been incredibly happy with it – it’s also made of sintered glass.

However, just like all ceramic rings are not created equally, I doubt all sintered glass media is created equally and I would be hesitant to recommend a product I have not used.

Thank for so very much. A very informative article. Answers everything I could think asking in relation to ceramic balls.

really nice article Ian, thanks very much for the informations provided.
Also I was wondering, do you think one could use ceramic ring filter for human drinking water ?

Hi Kaze,

Ceramic aquarium rings are designed for bacteria to grown on. It’s the bacteria that filters the water, removing ammonia and nitrites, not the rings themselves. I personally wouldn’t use them as a filter for drinking water.

Hello Ian,

You are professional and thank you so much for this article really good, and i have a question : has many different ceramic rings and they have a product that is named JBL Sintome. It absorbs NH4 and No2 and another product Micromec absorbs Nh4 No2 No3 so what the differece and why doesn’t Sintomec absorb No3. For me I recently bought Micromec but if Sintomec doesn’t absorb No3 its better for my plants, can you tell me is it real what they said or just another product to sell and thank you so much?

Hi Tarek,

Unfortunately, these two products are not available in the US. However, the bacteria that breaks down nitrates are anaerobic, meaning they live where there is no air. Deep inside rock and filter media. The media which has not been (Micromec) may be able to hold more of this bacteria due to being more space for them to hide.

The reality is that while this media may help remove some nitrates, you’ll still have to perform regular water changes – it’s not going to drop your nitrates down to zero.

In freshwater tanks, most fish keepers just use regular ceramic rings, in this case it would be Sintomec.

If you run a planted tank, test your water. If you still see nitrates there, then this ceramic media shouldn’t cause any issue.

Hi! We’re trying to establish a 10gallon tank with an HOB filter with stuffed filter floss and ceramic rings. My friend insists that the arrangment of the filter floss and the ceramic rings don’t matter and placed the ceramic rings right under the entrance of the tank water into the filter and stuffed the remaining section where the water flows out with floss. The occupied volume ratio is 1:2 ceramic rings to filter floss. I really want to switch the placement and the ratio but they insist that it shouldn’t matter. We have white bacterial bloom but no conversion of ammonia to nitrites. Am I being too paranoid that the bacteria is not properly adhering to the media because it’s clogged? Should I just be more patient? And does the arrangement of filter media in HOB filters really not matter?

Hi AK,

Filter media arrangement certainly does matter. While the arrangement won’t affect your cycle at all, it’s less than ideal. The ceramic rings will trap gunk and need to be cleaned on a regular basis. Just how quickly they accumulate gunk entirely depend on what you have in your tank, but as they clog, it will inhibit the amount of oxygen that can flow over the beneficial bacteria which can result in a die off. Not only that, but if not removed trapped gunk will further decay, which can need to faster rises in nitrates.

Filter floss is a particularly fine mechanical filter. While it can be used as the primary mechanical filtration, it will clog quicker than say a coarser sponge, which can inhibit water flow through your filter. Many people use a coarser media before filter floss to trap the big stuff while filter floss takes out the fine particles leaving your water crystal clear. If you have no room for an extra sponge inside your filter, you can always look into pre-filter sponges.

So to clarify, the order should be, from first to last:

Coarse Filter Media, Filter Floss, Ceramic Rings.

While you can skip the coarser sponge, you will have to make sure you are on top of your maintenance routine and regularly rinse your filter floss.

Hi, would it be possible to put my rings in a bucket with a heater and air hose, and use bacteria in a bottle with ammonia to jump start my media??? I need to wait 30 days before my tank stand is made and shipped so would love to get a jump on my good bacteria. I think it sounds good but you are the boss on this one. Thanks for your time.

Hi Bill,

It’s a crude way of doing it but it’s certainly feasible. If you grab a filter media bag to keep the ceramic rings together and place them over an air stone from your air pump this will generate current through the rings which will allow the beneficial bacteria to filter the water as it passes over them. From here you would just need to monitor your water parameters as per a usual fishless cycle.

It’s worth mentioning that this is how many fish keepers keep their beneficial bacteria alive during a power outage, when the filter no longer works – with a portable air pump.

Thanks for such a great article.It probably answered all my questions about the crematic rings.Thanks a lot.

Great article! Thanks! May I ask, I have recently bought a new filter as my old one has a minor leak. I have them both running presently to build up bacteria in the new one and will do so for about a month before removing my old one. Is there any benefit to adding the old bio rings to the tank substrate? I have a large log in the middle of the tank so they would be hidden and there is good flow in the tank.


Hi Hannah,
Some beneficial bacteria will hang out in the substrate, but as far as adding rings there goes, it will be of minimal benefit. You see, beneficial bacteria requires a surface to cling to and your substrate gunks up over time (it doesn’t have the same mechanical filtration your filter provides) so it likely won’t contribute a whole lot of biofiltration to your tank. However, I see no disadvantage to doing it, so it’s entirely up to you.

You mentioned that if we replace ceramic rings we will remove the bacteria. but doesn’t the sponge in my filter also holds loads of bacteria?

Hi Sam,
You are correct. This article is about ceramic rings, so that is anything found in this guide refers to them specifically, in isolation of everything else. If you have both, then some beneficial bacteria will be found in the mechanical filtration (the sponge) but most will reside in the biomedia, in this case the ceramic rings. The amount a sponge will hold will generally depend on it’s coarseness and structure, but still should pale in comparison to the surface area of a good biomedia.

Hi Sir,

A very informative article. In fact I have gone through a lot of your articles and they are well laid down.

I am wanting to use this filtration system for a large pond of 200 x 200 feet dimensions. Kinds of RAS Farming. I shall be using two-three layers of mechanical filters first – very fine sieve net kinds, sponge, pebble (plenty) and then the biofilters.

I don’t know if i am right or not. After going through your articles i am thinking of placing the Bioballs first with oxygen supply, then Ceramic Rings and in the last Activated Carbons. It from from here then the filtered water goes back to the pond.

I have a few questions sir –

1. What do you think, is the process flow correct.

2. By Bioballs the Amonia breaks to Nitrites and then to Nitrates (as i gathered from your bioballs writeup). By Ceramic rings you say it breaks Nitrites. My question is what does it break to these Nitrites.

3. Do I need to do something or put something on these media for the beneficial bacteria to grow or it will grow on its own.

4. Do I need to check the type of bacteria that grow in these colonies. Why this question because, it came to my mind that if good bacteria finds home in these media then likewise the harmful bacteria shall also find the home suitable. So how do i know what kind of bacteria is my biological filter carry.

I think its been a long narrative sir. So I shall stop here adding that I really loved your articles and could understand a lot of things from your article and therefore am in a position to ask these questions.

Had I not understood your article, I would not have asked questions 🙂 🙂 🙂

Thanks in advance.

Rgds, Sanjay

Hi Sanjay,

1. I can only answer your question in regards to aquariums. I have no experience in aquaculture and farmed fish. First you need a mechanical filter, otherwise the biomedia will trap debris and gunk, leaving less surface area for the bacteria to cling to.

2. Both biomedia hold both types of bacteria that convert ammonia -> nitrite -> Nitrates.

3. The bacteria will appear there on it’s own through a process known as “cycling” look this up for more information.

4. There are bacteria everywhere. While these are beneficial bacteria, there will certainly be other bacteria that seem to have no effect on the tank. However, only a few types of bacteria are nitrifying, so these have been singled out as beneficial. I do not know any fish keeper who checks for bad bacteria.

Thanks for lots of information,
I have question in my mind that when ammonia water from fish tank passes through bio midia
where good becteria resides, so how can the bacteria break the ammonia in nitrate in such a small time which takes just to flow through.
I mean ammonia water keeps flowing from inlet of biomedia and goes out of biomedia with ammonia reduced.
Please reply

Hi Jafar,

You are looking at it linearly. In practice, water doesn’t just pass through the filter and over the bacteria once. It’s continuous. Depending on the amount of ammonia and beneficial bacteria in a tank, it can take many many passes. This is why when cycling, the ammonia won’t drop for days or even weeks until the bacteria grow in a high enough number to remove ammonia and keep it at zero.

HI Ian
I have also had tropical tanks here in Oz for 30 odd years
typically with filter media – mainly carbon and sponges but have always done monthly 3/4 tank Water change
in the last couple years i had a pump change – normally never an issue – this one does have ceramic rings, which had been in place for at least 2 years.
i have typically rinsed them ( in rain water ) – i actually normally get water from another water source ( and de-chlorinate it )as I have all rain water – do use it a bit – maybe 1/5 volume with salt additives to enhance the soft water if i add it to the tank
I have never had a cloudy tank occur but in my not so wise moment choose to completely replace the ceramic beads 6 weeks ago – this lead to after 1.5 weeks of course cloudy water occur
so i did a 70% change with gravel filter ( as mine siphons out the window into the garden conveniently) , cloudy water disappeared but after 1.5 weeks re-appeared

i am a scientist and did pH test (7.1) and ran for nitrates – will actually have to determine correct amount as my lab instruments don’t determine the quantity ( but i can see nitrates present)

Reading both water change method to get tank back to clear and here – it seems that with mine still clouding but with nitrates present – that perhaps the tanks hasn’t finished cycling yet

will have to double check the ammonia and nitrite levels – with nitrates present would hopefully have these nearly in control – but still clouding happening 2 weeks after water change

SO would be few more weeks of perhaps 50% water changes would see me reduce this issue
wasn’t sure if should add more carbon to help with the filtration issue
have 2 pumps running in the 4 ft tank ( holds near 100L from memory will double check the volume) and is stocked – but not over stocked with fish

had been doing 4 – 5 weekly regular gravel filtering with 75% water change.
your feedback is greatly appreciated

Hi Krys,

Always nice to meet another passionate fishkeeper. I can imagine as a scientist you would love this hobby. After all, most of it comes down to, well, science!

If I understand you correctly, you replaced your ceramic rings in an established tank?

If so, it’s likely that you crashed your cycle. Without the beneficial bacteria to “filter” ammonia and nitrite, it would have spiked, which could certainly have caused the cloudiness which is commonly seen in new cycling tanks.

I’d suggest buying an API test kit, it has every test needed to see out a cycle. I just had a look at the price in Australia and I’m pretty shocked, about $60. We pick them up in America for less than $20. Perhaps you have cheaper test kits under a different brand? Regardless, you’ll need to test your ammonia and nitrite in order to get a better understanding of where in the cycle your tank actually is.

From here, your main priority will be protecting your fish, depending on the species, ammonia and nitrite tolerance of most fish is near zero. The solution is regular water changes or some water conditioners also “bind” these toxic chemicals.

Ordinarily you would swap out half of the ceramic rings at a time then wait a month or so before swapping out the other half, this way the bacteria can spread to it’s new home without causing a crash.

On the activated carbon, it doesn’t really do much except remove bad smells, tannin, phenols and certain medications. If you have driftwood or similar organics, then these can leach tanins and stain your water. This is the most common use here in America. I don’t see how it would help here. Also, be mindful that activated carbon can only “absorb” for so long. Typically you’ll get around a month of use before it needs to be replaced. It doesn’t take long for the tiny pores to clog. Don’t worry if you forget to replace it, it won’t leach back into your water.

I have a 4o7 fluval with 4 trays .the bottom one has filter pads ,next is carbon ,the last 2 are filled with ceramic rings… What order should I have them? Rjk thanks!

Hi Rjk,

It goes mechanical filtration first (foam/sponge) then biological filtration (ceramic rings/biomedia) then Chemical filtration (resin, phosguard, activated carbon)

I have a Top Fin Silentstream 40 Power Filter and its chemical filter is built in the mechanical filter (the activated carbon is inside the filter floss). It also has a bio-cartridge which is placed after the mechanical/chemical filter. Will this arrangement have any affect on the nitrifying bacteria? Also could you explain why the chemical filter should be placed after the bio filter?

Hi Clariynotclaire,

Those 2-in-1 (filter floss + carbon) disposable filters are a bit of a scam and if you can ween yourself off them, you probably should. These things are designed to break down and not be reused, which is just poor since the filterfloss also houses good bacteria and you are disposing of these each time you toss the filter out, not to mention that replacing it continually is expensive.

If you have room, my preference is always a dedicated sponge and ceramic ring combination, added to the filter seperately. You don’t need activated carbon – it soon clogs and is only useful for removing tannins, bad smells and certain medications – if you are properly maintaining your tank, activated carbon can easily be skipped.

Chemical filters should always be added last as ceramic rings or the media bag they sit in can trap gunk that may be the very thing you are trying to remove from your aquarium with chemical filtration

I’m quite new to fish keeping but my wife and I really wanted to get an aquarium just to keep community fish, we settled on a SuperFish 80 which on the stand fits perfectly in the space available, we’re purposefully under stocking about 24 fish in total and 8 shrimps (amano).
I need to extend planting a little as the shrimps took a liking to 3 varieties and stripped them bear so I’m ‘re planting with the 3 they didn’t like ????….we really enjoyed your reviews and the one relating to activated charcoal opened our eyes so we’ll be purchasing your recommendation.
Many Thanks

Hi Andrew,

I’m unfamiliar with the SuperFish brand, I assume you are from outside the USA? It sounds like you are all over it, especially with your trial and error experience with your shrimp! Thanks for the kind words and I wish you all the best in the hobby. Warning: It’s very addictive.

Dear Ian,
I have an AquaClear 50 filter. I am trying to find bio rings/media the same size as the ones that came with the filter new.
I ordered some and they were to large for my filter. They are at least 4 times the size of the original bio rings (stones is abetter description).

Hagen, the manufacturer said the bio rings were not designed for my filter and said I could only buy their pre-assembled bio bags.
I also ordered some mesh bags but they are to fine for bio material IMO. So they are going to be returned.

My two questions.
Do you now where I can find bio-media that is the correct size for my AQ 50 filter?

Can I use the mesh bags that onions come in from the grocery store? (It looks identical to what I have and am using. Only difference is the color). Or how can I find the correct material to contain my bio media?

Hi John,

Why did you want to avoid the Aquaclear biorings? Is there a particular reason? I only ask as I know many fish keepers who have successfully used these rings. Sera Siporax makes a small version for HOB filters, I think it’s just called Sera Siporax Mini. These are a smaller version of what I use in my tank although admittedly I am unsure as to how small they actually are.

As for your question, it depends on the material. If it’s made from nylon, then it could be aquariums safe. However, there is no guarantee any chemicals or dyes used in it’s manufacture won’t leak into your aquarium. The rule of thumb is that if you don’t know what’s in it, don’t add it to your aquarium. coarse filter media bags are the product you are looking for, these are designed to hold filter media, have wider gaps and only cost a few bucks each. Just be mindful they do come in a variety of sizes, so check and make sure the measurements match with what you are after.

Hi Ian,

Your article is the most informative I’ve found on the internet so far. Now my question is, if you have 2 identical tanks with the same bio load, one with ceramic ring and the other don’t, will their nitrate level be different and how much ie: 80%, 50% or just 10% ?

Hi Tran,

Not a black and white answer. In an aquarium, fish are not the only thing that produce ammonia. Over feeding, plants type of food etc. can all impact the rate at which nitrate is synthesized. To further complicate this, in the absence of rings, beneficial bacteria also inhabit sponge, substrate, anything porous really.

Hey ian! Great article! So much information I’ve learned from it! I’m Currently doing my research to find the best biomedia for my planted aquarium. While surfing the web I came across Biohome ultamate. And seems to be the best thing to come into the aquarium hobby world. Yet there’s some things about it that don’t seem right to me. The fact that they state it removes nitrates? I’ve never heard of any filter media that can remove nitrates but a water change or atleast reduce them. To my belief I thought plants need the nitrates or at least some. Also that it can last anywhere from 10-12 years. Have you heard of this biomedia? And if you have is it a good choice for planted aquariums. Or are ceramic rings a better choice. Here is a statement from them. Thank you in advance. Hope to hear from you soon.

This media enables aerobic bacteria to populate the outer surfaces of the media, while the inner portions of the media house anaerobic bacteria. Oxygen is consumed by bacteria on the surface of the media which gives rise to anoxic conditions deeper within. Only anaerobic bacteria then have the ability to reduce Nitrates into Nitrogen gas, which then off gasses into the atmosphere. This type of media can reduce nitrates in a tank, where as conventional media only oxidizes ammonia into nitrates, which then build up over time. (but are easily removed through water changes)

Hi Christian,

To an extent, all ceramic biomedia can contain aneraobic bacteria. This isn’t a new concept and many brands use it as a selling point. But here is the thing: In a freshwater tank, in most cases, there isn’t enough room in your filter to store enough biomedia that will break down nitrates as quickly as they are produced. Besides, even if you could get nitrates down to zero, this won’t eliminate water changes as you still need to replenish trace minerals that are not naturally produced in a sealed aquarium environment.

As for last-ability, Sintered Glass media lasts an incredibly long time. My Sera Siporax is going on 8 years old now in my tank, and that was an old box I found that is likely from the 90’s.

It’s the aerobic bacteria that are most important, and for that, any old ceramic rings will do. However, some certainly do last longer than others.

Hello again. I ordered some ceramic rings and would eventually like to use them once the poly floss + carbon cartridges that my filter came with are due to be changed out.

I’m trying not to overthink it, but it there are too many choices of filter media for my little brain to handle. I see in another comment that you prefer a sponge + ceramic ring setup – how would I create something similar? Do I need a filter pad or floss, too?

I’m a little puzzled on where the sponge really ought to go… following the directions for my filter gives me floss-carbon-sponge, in that order. The manufacturers seem to be considering the sponge as a bio medium, not a mechanical medium. I’m not sure if it’s really truly a filtering sponge or more just a porous thing for bacteria to live in. If there is such a difference, that is. Would I need to place it somewhere different if I changed from cartridges to a pad/floss and ceramic rings, or should it stay put?

If there’s no floss or pad, do I get a different, more spongey sponge to do the mechanical filtering and protect the ceramic rings from gunk, and again leave the existing sponge put, thus arranging it sponge-rings-sponge?

Obviously, I am confused. Any help would be appreciated. Though I probably do have a month or more to decide. I don’t want to end up shelling out for cartridges when I could probably do better for cheaper. Cheers 🙂

Hi Again Shea,

I know it’s a lot to take in all at once but you’ll get there 🙂

Try and add as many ceramic rings as you can before you swap out the existing cartridges – this will give the beneficial bacteria time to move to it’s “new home” I’d recommend leaving them in this arrangement at least a few weeks before making the complete transition.

Typically you would arrange your filter as follows:

Water flow into filter->
Coarse sponge ->
Fine sponge (such as filter floss) ->
Bio media ->
Chemical media (such as activated carbon) ->
Water outflow to tank

Chemical media can be skipped and often only one type of sponge is used. The finer the sponge, the quicker it will clog, this is why my preference is for a coarse sponge to trap the big gunky bits then filter floss to capture all the tiny bits, resulting in clear water.

You can always use a pre-filter sponge if your filter allows it. This essentially moves the coarse sponge to the outside of your filter, these can be purchased separately.

Regardless of how you do it, you want a sponge before the ceramic rings – the beneficial bacteria cling to the pores of the ceramic rings. If these pores clog, it means less bacteria can call them home.

Please let me know if you need anything clarified here!

I was looking at pre-filter sponges and getting baffled, you’ve cleared that up a bit for me, whew. (I think I might go pick some up from the pet store in person to make sure I’m getting a size that will fit my filter intake tube – a lot of the ones on Amazon seem too small for what I have, but it’s hard to tell. Others don’t seem coarse enough and I was worried they’d block my water flow.) Anyway, using that instead of the existing sponge would really free up space inside the filter for the rings so I can put them in the right spot and get them colonized.

Okay, I think I understand. I will go prefilter sponge + floss + ceramic rings, and I’ll try to get it all going ASAP and just replace the cartridge with fresh floss in a few weeks.

Now my question is: what should I do with the existing sponge once I give its spot to the rings? I don’t know that there’s much bacterial activity in it just yet, should I toss it? Chop it up in pieces and stuff it somewhere else?

Thanks a million 🙂

I’d say that’s a good idea going to see the pre-filters in person. Once you know how sizing works and what to expect, it will be easy to order online!

Ordinarily I would say to squash the previous sponge into the same cavity as the ceramic rings but because you have only just started the cycle, this is a judgement call only you can make – at worst, you’ll only delay the cycle a few days by disposing of it entirely.

Ian you are my savior. Your article was so informative and helpful. I have turtles not fish and I had run into a HUGE ammonia issue. Even with 80% water changes the water was still 8.0 ammonia. The tank is over 120 gallons and over a year old. I know it has good bacteria. It’s just not enough after reading your article. It all makes sense now. I have 3 slider turtles all full grown. Lots of pollutants. Need more good bacteria to grow. I have tripled my ceramic rings and feel so relieved to finally understand the aquarium dynamics. I have a fluval 406 canister pump which works great, just need ammonia eating bacteria. Thank you for your article. So grateful I found it. Thanks again.

Hi Christina,

I’ll admit, I don’t know a whole lot about turtles but in a fish tank, Ammonia at 8.0 is a huuuuuuge concern. I’m sure you figured out that just because your card said 8.0, it could be anything over.

Here is a tip for next time to find the exact amount of ammonia if it’s off the charts – you can use a mix of RO/DI water and your tank water. For example 50% tank water and 50% RO/DI water. This would allow you to test up to 16 ppm (since you double the reading) Although in your cases, it sounds like ammonia was at extreme levels given the 80% water changes.

I hope your additional ceramic rings fix the problem. Just be mindful that the bacteria will need to take time to grow, so the fix might not be instant.

Thanks again for sharing your experience!

Hi Christina and Ian!
The good news is that turtles are not fish, and these ones you have are very hardy, they don’t relie on water purity like fish do, well, they breath air to start with. It is normal that the water is full of ammonia, they pee and pooh in their swimming pool after all but they don’t breathe it, so it is not a hazard to their health that much. Nevertheless, it is definitely a good idea to change the water often, 80% sounds good, or even 100%.

Hey Ian!

How are you? So I have a few questions regarding media placement. I have 2 aquaclear filters which tell me how to place the media (bottom- sponge – middle- carbon – top rings (i actually took out the carbon and just have to sponge and rings – I feel like with everything nowadays there is so much conflicting information in this hobby – I just read a very popular forum that so many people were arguing in the comments about the order of media in an aqua tech filter where you place the media front to back instead of top to bottom like a canister or aqua clear.

Which leads to my question- I am pretty sure I understand but just want to make sure. So I have my aqua tech hob filter, I placed the sponge in the back (closest to the wall) then I put a tiny bit of carbon, and last (closest to the water I put the ceramic rings) is this correct?

I also have a cascade pennplex 300 canister filter and that one I stuffed with sponge in the bottom, followed by some ceramic bio media, then a thin layer of padding i ripped apart from an unused aqueon cartridge, then a little more sponge, ceramic, and last a tiny layer a foam from the cartridge since the water flows through in the bottom and just up the filter.

I have this in the 4-gallon tank with luna (the one i was having the issues with and thought she was sick) well she’s doing great now but I just want to confirm that I am correct to have two filters running so I don’t kill the cycle. When will I know that the new filter is good to go and I can remove to aqua clear hob filter and move that to my 5 gallons? I dont know if you know about the top fin 5 gallons with the built in filter, however its a beautiful tank but the compartment is SO tiny. I have been getting algae in that tank on the decorations and walls and was wondering if I would put another filter on there along with the ineffective built-in one? I can’t fit anything in there anyway so I thought it would be fine… Just in case it’s not I am cycling a 10 gallon for him now so I might just move him!

Hi Dominique,

Good to hear from you.

As we have discussed before, in order that the water flows through them:

1. Mechanical filtration.
2. Biological filtration.
3. Chemical filtration.

This means -> Sponge ->rings ->carbon.

As for the two filters running, it shouldn’t cause any issues (you can never have too much filtration) the concern would be water movement, since betta do not like strong currents. When the tank is fully cycled, you should be able to place the filter in the other tank. Be mindful that it won’t instantly cycle, since luna can only produce so much waste, which in turn only produces so much food for the beneficial bacteria. If you move one of the filters to a new tank, it will need a little more time to catch up to a new fish tank but because you have given the beneficial bacteria a head start in getting established, the cycle will be much quicker than before.

I’m new to the hobby I’m in the middle of cycling my first tank (no fish) and I have a few questions. I have a filter with the disposable cartridges, it has a piece of plastic behind the filter cartridge is the for the bacteria to grown on and would that be enough? I also have a natural clay substrate and live plants is that enough to continue using the disposable cartridges and if not are the ceramic rings to replace the filter cartridges and can you put them in any filter?I believe my filter is a topfin “silenstream” can I take the disposable cartridge completely out and put another media in the filter?

Hi Andy,

Disposable filters are somewhat of a scam. The sponge holds most of the beneficial bacteria and that is designed to be disposed of. When you throw this away, you throw out your beneficial bacteria. Ceramic rings can be placed in any filter and you cannot have too much. If you are going to add ceramic rings, make sure you leave your disposable filter in there as long as possible (up to a month) as this will allow any established beneficial bacteria to migrate it’s way to the ceramic rings.

Hey Ian!

I have two aqua clear filters which i love and they make it very simple by showing you what order to place the media. Mechanical on the bottom, chemical middle and bio rings on top.

I have an aqua clear hob filter for my 20 gallon but took out the cartridge & replaced with sponge and bio rings.

You mentioned the order of media depends on how the water flows into the filter- how can I figure that out? Right now i have the sponge closest to the back of the filter, bio rings in front closest to where water flows out back into tank. I just cleaned filter last night and i cut a new sponge to add in there but im not replacing any bio rings. I was thinking about keeping the old sponge along with the new one just to be sure i dont get rid of any bb.

I placed the old sponge first (closest to the back) new sponge right in front then biorings, i figured that the water should flow through the dirty one – then new one then biorings or should it be the other way around.

Anyways please let me know that i am correct in placing the media from back to front , its confusing because aqua clear is bottom to top and some are side by side.

Thank you

Hi Dominique,

It sounds like you have this correct, working backwards, from the outflow the order would be biomedia (noodles, rings, etc.) then sponge.

Hi Qazi,

Yes, you can and they will work just as well, but they potentially won’t last as long as if you left them full sized.

I have a Whisper Micro Filter that came with my 5 gal from Walmart. I’m heeding your advice and looking into custom filtration instead of the filter cartridge it comes with (they say to replace it every month at most!!). There’s a lot of information that I’m trying to make sense of. So, questions. Does it matter if I keep the filter itself and replace the cartridge with the custom stuff or is there a specific filter one should use when going custom? As for arranging the media, I know you said coarse mechanical –> fine mechanical –> bio media, but is that going from bottom to top or back to front? I’m guessing it’ll probably depend on what filter, but it’s worth an ask. Do you have any recommendations for mechanical media for my situation? I definitely want to get ceramic rings- maybe there’s a specific mechanical media that works well with them? Finally, how can I switch over from the filter cartridge I have now to my own filters without wrecking the bacteria? As you know, I’m currently in the cycling process. I’m guessing maybe put some of the media in with my cartridge and leave it for a while to let the bacteria transfer, remove the cartridge, and put the rest of my media in, but that’s just a shot in the dark.

I know I sound like that 3 year old everyone knows who constantly asks questions, but hey, asking questions is the only way to get answers.

Hi Rosie,

Good questions.

It all depends on the size of filter you have. Annoyingly, a lot of companies have made the filters as small as possible to force people into continuing to buy cartridges. If you have room, and can squeeze everything inside, then your current filter will do. Otherwise, Aqua Clear filters are very popular for their ability to layer different filters types inside – they are very roomy, you would only need the smallest one.

The order depends on your filter. The coarse sponge goes wherever the water runs through first. Unfortunately, this will very according to the design of the filter. It could be at the top, side or bottom. You’ll need to figure out how water flows through your filter in order to position these correctly.

For mechanical, “aquarium sponge” comes in sheets and you just cut it to size. It’s the most affordable. There isn’t really a “mechanical” filtration that works best. It either works or it doesn’t – it’s job is to catch all the floating poop, uneaten fish food and other gunk that is in your tank and trap it, and stop it reaching your ceramic rings.

Your thoughts are almost spot on with how to swap over the filter media. If you look at your filter cartridges, they will probably have a fluffy cotton-like material on them? (some have ceramic rings inside them, but they are not common) if they do, remove this fluffy material and lay among your ceramic rings. Any bacteria that is in them will soon move to the ceramic rings. Then replace the cartridges with sponge. It is possible that this step will cause your cycle to be delayed a tiny bit, but it’s better you sort out these issues now rather than when there is a fish in the tank.

Oh, and I admire you for asking lots of questions! 30 years ago I was in the same boat, and just like you, I learned by asking lots of questions too. It’s the ones that don’t ask questions and just assume that are the worry!

They say you can keep that plastic piece in there with your sponge and bio rings it’s another place that builds beneficial bacteria, I’m a yr into getting technical, Only because I have a gold fish that my GRANDAUGHTER won at carnival and 4 tanks later amd almost 4 yrs. Buddy is HUGE, and I cant let him go. so I have been through many many tanks and now debating to move him out of the 20gl and in this 20gl I kept the blue plastic “cover I call it” in with all my sponge floss and bio rings Its a good thing to have also to start up another tank ,

Hi Tammy,

Gold fish can grow to be huge and need large tanks to accommodate them. I have to applaud you for taking the time for caring for your the fish your granddaughter won. The world needs more people like you 🙂

hi i am maxine i would like to use the bio ceramic rings in a filter i made via you tube it works well but i have to clean it regularly. can they go in the bottle with out a bag.

Hi Maxine,

You can use ceramic rings without a media bag. However, a bag will greatly simplify the cleaning and replacement process once they finally do deteriorate.

Fluval claims that their C-nodes are better than ceramic rings and I have some in my C-3 filter but my 80-gallon has a fluval 407 with ceramic rings, activated carbon, ammonia remover, water polishing pad and recently I swapped out my Topfin 40 for the C-3 in my 40 gallon tank (only has a gap in the lid made for 1 filter) and I had nowhere to put the Topfin 40 so I placed it on the back of my 80-gallon after cleaning it. It has activated carbon inside a filter cartridge bag (mechanical filtration) and a blue plastic bio-cartridge which I think is used for storing BB but I want to add some C-nodes to the back of the filter. Is that ok without a bag

Hi Tom,

Isn’t that just like a company to say their product is best? To answer your question, it should be fine to add the C-nodes without a bag. However, if they begin to degrade like regular ceramic rings, you may find it difficult to replace them without them crumbling into tiny pieces which you then have to collect.

G’day mate thanks for the article. Do you know what the beneficial bacteria is called? Do different media house different kinds of beneficial bacteria. I’m thinking about using marinepure and noodles in seperate filters. Would this increase the variety of beneficial bacteria? Cheers, Simon

Hi Simon,

Nitrosomanas and nitrobacter are the two beneficial bacteria that live in your filter that do the heavy lifting. While it’s highly likely that there are other bacteria living among these colonies, they don’t oxidize ammonia and nitrites in the same way. To this effect, it’s best you just focus on a filter media with as much surface area as possible, since it gives more room for the bacteria to cling to. Whether you go all out on one type of biomedia or mix it, the surface area is the most important.

Hi Tammy,

I’m curious how this worked for you. I’m currently doing the same thing, moving a 5″ comet goldfish from a 20 gal to a new 55 gal that I’m setting up using ceramic rings. I plan to use mechanical filtration first and then the rings, leaving the blue plastic pieces in the HOB filter and seeding from his current tank gravel and established filter media.

Any advice would be appreciated as well as comments from others.


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