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You spot one. A wiggly white worm crawling up the glass like it pays rent. Next day? Five more. And your shrimp? They’re acting weird… or worse, gone.
Congratulations, you’ve got planaria, the flatworm freeloaders that turn peaceful aquariums into ghost towns. Don’t freak out (yet). Here’s how to spot them, kill them, and keep your shrimp alive without nuking your tank.
Table of Contents
Worms Crawling Up the Glass? How to Tell if They’re Planaria
You’re not crazy; there really is a tiny white worm inching up your tank wall, as if it owns the place. But is it actually dangerous… or just gross?
Here’s how to identify planaria worms in seconds, before they start multiplying like wet gremlins. Planaria worms have:
- A flat, wide body
- A distinct triangle-shaped head
- They measure around 0.1 to 0.6 inches
- A gliding, creepy-calm crawl (they don’t wiggle like other worms)
- A weird habit of cruising across your glass at night like they’re on patrol
Basically, if it glides like a slug, has a triangle head, and shows up after dark, it’s probably planaria.
2 Types of Planaria You Might See
There are actually two common types of planaria worms found in aquariums:
- White planaria (Procotyla) are the most common. They have a triangle-shaped head and often glide across the glass where you can easily spot them.
- Brown or black planaria (Dugesia) tend to live in the substrate and come out at night. They’re sneakier, but just as dangerous to shrimp and snails.
To make things even more confusing, some types of planaria can change color depending on what they eat. Colored flakes, for instance, can turn a planarian a lovely shade of pink.
Besides the color, they are nearly identical in appearance. Both types reproduce like crazy and pose a threat, especially in shrimp tanks.
Not All White Worms Are Planaria
Other harmless aquarium worms, like detritus worms and rhabdocoela, often show up in overfed tanks too. Here’s the difference between planaria and these other worms:
| Worm Type | Head Shape | Movement | Good or Bad? |
|---|---|---|---|
| Planaria | Triangle | Smooth glide | Bad, shrimp killer |
| Detritus Worm | Round | Wiggles like mad | Harmless |
| Rhabdocoela | Round | Fast, darting | Harmless to adult fish |
The pesky planarian is often confused with another flatworm, the rhabdocoela. Rhabdocoela is similar in size and color to white planaria. However, when compared side by side, the differences become clear.
It’s all in the shape of the head…
On the left, you have a planarian – its tell-tale triangular head makes it easy to spot. On the right, you have a rhabdocoela, which has a rounded head.
It’s important to know which is which because rhabdocoela do not respond to many treatments that will kill planaria outright.
Another way to tell them apart is their quirky cross-eyes. To see this, you’ll need a magnifying glass or the zoom function on your phone.
Yep, this shovel-faced pest is also cross-eyed. At the tip of the head are what look like two eyeballs with pupils facing each other, as you can see in the above picture.
Wierd Worm Fact
Planaria are possibly the weirdest worms that will ever visit your aquarium. Their unusual traits make them widely studied in the scientific community…
Perhaps the weirdest thing is that when you cut one, say into five pieces, it will regrow into five different planaria. This is why it’s a bad idea to crush any planaria you find in your aquarium. Carry on reading to learn even more weird facts about them…
Why It Matters (Especially for Shrimp Tanks)
If you’re seeing planaria in your fish tank, the danger mostly depends on what else is in there.
Fish-only tanks? You might get away with ignoring them for a bit. But I still wouldn’t advise it. Planted tanks with shrimp, snails, or eggs? You’re on a ticking clock.
If you see planaria in your aquarium, assume they’re already laying eggs, hiding in your substrate, and looking for something soft to snack on.
Up Next: How you accidentally created the perfect planaria buffet. Don’t feel bad, most infestations start with good intentions, like feeding your shrimp a little too much.
Why Planaria in Fish Tanks Happen
You didn’t mean to start a worm outbreak. But to planaria worms, your tank is basically a luxury resort with free food, no predators, and 24/7 room service.
Let’s break down how they got in and why they’re multiplying like it’s Black Friday at the buffet.
How Planaria Sneak Into Your Aquarium
Even well-maintained tanks can get infested. Planaria are stealthy little freeloaders that hitchhike their way in through:
- Live plants from stores or other tanks
- Used equipment like nets, filters, and gravel vacs
- New fish, shrimp, or snails that weren’t properly quarantined
- Transferring substrate or décor from another tank
They don’t show up right away. They stay buried in the gravel or sponge filter until conditions are just right, which is usually when extra food starts piling up.
Why Planaria Love Your Tank So Much
Here’s what makes your aquarium irresistible to planaria:
- Overfeeding — excess food sinks to the bottom = free buffet
- Rotting plant matter — especially in planted tanks
- Dead snails or shrimp — soft tissue is a delicacy
- No predators — shrimp tanks rarely have anything that eats worms
- Eggs — planaria will eat shrimp eggs before they even hatch
This is why planaria in aquariums are such a problem: they feed on the exact things you’re trying to protect.
How Fast Do Planaria Get Out of Hand
Planaria don’t breed like normal animals. They clone themselves.
Cut one in half? You now have two. Cut one in five? Congrats, you just started a colony. Leave them alone? They’ll lay eggs on the glass, in the gravel, and deep inside your filter sponge.
White Vs Black & Brown Planaria
Black and brown planaria flatworms feast on waste. Biofilm, uneaten fish food, and even poop – it’s all a tasty meal to planaria. If you notice these planaria, it’s often a sign that you are not maintaining a clean tank.
If you are nodding your head, rinse your filter, grab your gravel vacuum, and perform a water change – and get into the habit of doing it regularly!
White planaria, on the other hand, eat small worms, shrimp, and even live foods such as daphnia or bloodworms. If your tank has an abundance of food for white planaria, you will soon see them multiply in number.
We have a guide on the best water changers to make the weekly water changing process smooth and easy.
Some aquarium pests are annoying but harmless. Planaria worms aren’t one of them. Next, we’ll look at what they kill, how they do it, and how to stop it before it’s too late.
Are Planaria in Aquariums Dangerous?
At first, planaria just look gross. But give them a few days, and you’ll start noticing your shrimp population doing a slow vanishing act.
This isn’t just a nuisance worm. Planaria worms can and do kill.
What Planaria Do to Shrimp & Snails
Planaria are soft-bodied flatworms with a taste for even softer prey and zero chill when it comes to hunting at night.
Here’s how they wreck your tank:
- Smaller shrimp disappear first, especially babies
- Shrimp and snail eggs get eaten before they can hatch
- Snails stop moving or flip over and die
- Shrimp get stressed, stop eating, and molt poorly
- You wake up to fewer and fewer survivors each day
They don’t bite like predators. Instead, they crawl onto soft-bodied animals and secrete a paralyzing slime that slowly suffocates or poisons the victim.
If this slime touches the belly of your shrimp, or if planaria crawl under the exoskeleton, it will stun your shrimp, and then planaria will happily eat it alive.
Are Planaria Dangerous in Fish-Only Tanks?
It depends. If you’re only keeping larger fish, planaria might just live quietly in the substrate. Some fish even eat them.
But if your fish are small, delicate, or you have fry (young, recently hatched fish still in their juvenile stage), planaria in a fish tank can still cause problems, especially if food or bio-load accumulates.
Are Planaria Dangerous to Plants?
Planaria won’t eat your plants, but they will love your planted tank:
- Soft substrate
- Rotting plant bits
- No predators
- Higher chance of overfeeding
So while they won’t chew your anubias, they’ll absolutely thrive in your beautiful aquascape and go after the creatures living in it.
One of the easiest ways to maintain a balanced aquarium is by choosing the right plants from the start. Check out our guide to the best aquarium plants for beginners: low-maintenance, shrimp-safe, and nearly impossible to kill.
What’s More Dangerous? Brown & Black Vs White Planaria
Brown, black, and white planaria are dangerous, but each in its own way.
White planaria are aggressive predators and are particularly dangerous to shrimp. Shrimp eggs and baby shrimp make a tasty meal. However, it is not unheard of for hungry white planaria to go after adult shrimp, too.
While brown and black planaria do not hunt shrimp, they are more than capable of killing them. You see, planaria move on a slime trail, just like snails. However, unlike snails, the slime that planaria release contains a toxin that is deadly to shrimp.
The bottom line? If you’re seeing planaria in your aquarium and you have shrimp, snails, or fry, treat it like an emergency. They won’t stop until something stops them.
Coming up next: how to kill them safely, completely, and in just two days.
The 5 Step Planaria Kill Plan (Safe for Shrimp, Snails & Plants)
You’ve confirmed it: those triangle-headed creeps on your glass are planaria worms. Now you want them gone, without nuking your shrimp or melting your moss.
Planaria are notoriously difficult to remove from your aquarium. If you miss a single flatworm, it will multiply into many.
So, here’s exactly how to wipe them out, fast.
Step 1: Starve Them
Planaria only thrive when there’s food.
- Stop feeding your tank for 24–48 hours
- Remove any leftover food, dying snails, or decaying plants
- Light vacuum the substrate, but don’t disturb too much if you have shrimp
No food = slower reproduction = easier to kill.
Step 2: Trap the Survivors
Use a DIY planaria trap or buy one online.
DIY option:
- Take a small plastic container
- Poke tiny holes with a toothpick (small enough that shrimp can’t enter)
- Add a piece of raw shrimp, fish food, or raw chicken inside
- Sink it to the bottom at night
- Remove in the morning, and it should be full of planaria
I recommended this planaria trap. I have personally tested it and can confirm it’s well-made and more than capable of capturing planaria – bait it with raw chicken! Watch this short video showing how they move, how they kill, and how many a trap can catch in one night.
Some tank enthusiasts might suggest using these alone. And while there’s no arguing that they work, they rely on your planaria being hungry. If the planaria are not attracted to the bait you placed inside, then it’s as good as useless.
Plus, there is no guarantee that you will capture every single planarian in your aquarium. This is why it’s essential to use a planaria trap (emptying and rebaiting it every morning) and perform the tank treatment (see step 4).
Step 3: Remove Your Chemical Filtration
Your carbon filter or purigen can remove the Fenbendazole from the water before it has a chance to work its magic. Remove it and replace it after treatment is finished.
Step 4: Dose the Tank Safely
Use Fenbendazole (sold as Panacur C), a dog dewormer that effectively eliminates planaria in aquariums without harming shrimp or snails when administered correctly.
If you have ever treated your dog for worms, you will be fully familiar with this product. I was actually introduced to this product by a friend at my local fish club who used this shrimp-friendly way to kill hydra.
And, it works just as well at getting rid of planaria!
The secret ingredient? Fenbendazole. It will eradicate a planaria infestation in just a few days. It’s like a planaria nuke!
Panacur C comes in different sizes. I personally recommend buying the packet that has 3 x 1g bags, as it will make measuring easier – a little goes a looooong way.
Before you drop this product in, be sure to remove any snails and sensitive shrimp you want to keep. Fenbendazole can be lethal to those, too! Malaysian trumpets and Nerite snails, in particular, seem to be affected.
Dosing Instructions (Standard Tank):
- 0.1g of Panacur C per 10 gallons
- Crush the powder, dissolve in a small cup of tank water
- Use a turkey baster or syringe to evenly distribute it in the tank
- Leave the lights off for a few hours, as planaria are more active in the dark
- Perform a 25–50% water change after 24 hours
- Repeat once after 2 days if needed
A gram scale makes measuring incredibly easy – I use this in fish keeping all the time to measure out doses. Sprinkle this powder into your tank.
Important: Always dose low and test on a small tank if you keep rare shrimp. Panacur C is considered safe, but overdosing can mess with bio-filtration in delicate setups.
Step 5: Redose
Wait 48 hours (2 days) and reapply the same dose.
And just like that, your planaria problem is cured.
The 2-Day Planaria Kill Checklist
- No feeding for 48 hours
- Set a nightly DIY trap
- Dose with crushed Panacur C (0.1g/10 gal)
- Turn off the lights for a few hours
- Water change after 24 hours
- 2nd dose after 2 days
What to Expect After Dosing
- Planaria worms will die and fall off surfaces
- Your filter may cloud slightly; that’s normal
- Don’t vacuum aggressively, as dead planaria release toxins
- Let your filter and beneficial bacteria clean it up slowly
Treat once, treat right, and you won’t see a single worm on the glass by the end of the week.
Up next: the one mistake that makes planaria come back even stronger (and how to avoid it).
The #1 Mistake That Makes Planaria Come Back Even Stronger
You followed the kill plan. You saw dead planaria. Your tank looked clean. Then, a week later, they’re back. Stronger. Slimier. Smugger.
Here’s what probably happened: Overcleaning right after treatment.
When planaria worms die, they don’t just disappear. Their bodies release toxins, and if you vacuum too aggressively or stir up the substrate, those toxins spread through the water faster than your filter can handle.
The result?
- A mini ammonia spike
- Shrimp stress or deaths
- A few planaria egg capsules survive and hatch into a brand-new infestation
So, once you think you’ve killed all the planaria, next you want to use your trusty aquarium test kit and closely monitor your ammonia levels over the coming week.
This is particularly important if your aquarium was overrun with planaria. You see, those bodies are going to break down, and as they do, they release ammonia into the water. So, you want to catch it fast if your ammonia levels spike.
Why You Should Let Your Filter Do the Dirty Work
Your tank’s bio-filtration is built to break down waste slowly. If you do a full gravel vacuum or scrub everything clean too soon, you disrupt that process and give the surviving planaria a chance to bounce back.
What to do instead:
- Spot-clean only for 48–72 hours after dosing
- Use a poly filter or activated carbon to help absorb toxins
- Don’t stir the substrate deeply, especially in shrimp tanks
- Avoid overfeeding again too soon
Did You Dose Correctly?
Some planaria survive because the dosage was too low or uneven.
Double-check:
- Did you crush and dissolve the Panacur C fully?
- Did you turn off the lights so the planaria would come out and get exposed?
- Did you follow up with a second dose a few days later?
If not, the survivors probably laid eggs while you were patting yourself on the back. I told you, they’re pesky.
How to Know They’re Really Gone
- No worms on the glass, even at night
- No twitchy shrimp or missing snails
- No planaria caught in your trap after 2–3 days of trying
- Tank is clear, steady, and stable
Coming up next: how to keep them gone for good, without turning into a paranoid tank parent forever.
4 Planaria Prevention Tips for Lazy (But Smart) Aquarists
Good news: killing planaria is the hard part. Better news: keeping them out doesn’t take much, unless you love overfeeding and chaos.
Here’s how to stop planaria worms from ever crashing your tank again.
1. Quarantine Everything
Plants. Shrimp. Snails. Decorations. That sketchy bit of moss you bought from someone on Facebook. Always assume new items are planaria delivery vehicles until proven innocent.
Quick quarantine checklist:
- Rinse and inspect plants under white light
- Hold shrimp/snails in a spare tank or tub for 7–10 days
- Add a poly filter or media from your main tank so you don’t crash the cycle
- If you spot a worm? Treat before adding anything to your display tank
2. Feed Less Than You Think You Should
The #1 cause of planaria in fish tanks is overfeeding, especially in shrimp setups.
If food is rotting on the bottom after two hours, you’re feeding too much. If you “can’t tell” how much they eat… feed even less.
Tips that work:
- Use feeding dishes to control waste
- Drop food at the same time each day, so uneaten bits are easy to track
- Fast for one day per week. Trust me, your shrimp can handle it
3. Clean, But Not Like a Maniac
You don’t need to vacuum every inch of your substrate every week. In fact, aggressive gravel vacs can stir up buried planaria eggs or crash your cycle.
Instead:
- Spot-clean visible gunk
- Use shrimp or snail-safe tools
- Swap filter floss monthly
- Replace sponge filters every 6–8 weeks (or deep clean them in tank water)
4. The Night Test Trick
Want to be 100% sure your tank is clean?
- Turn off your tank lights.
- Wait 30 minutes.
- Then shine a white LED flashlight across the glass near the substrate.
If you see planaria worms gliding along like they own the place, the infestation isn’t over.
Do this test once a week for a month after treatment. Yes, it’s gross. Yes, it’s weirdly satisfying when you see nothing.
Next up: the weirdest planaria facts you’ll wish you didn’t read.
5 Weird Planaria Worm Facts You’ll Wish You Didn’t Know
You’ve seen them on your glass. You’ve watched them wipe out shrimp. But you haven’t even met the worst side of planaria worms yet.
These things are part worm, part horror movie, part science experiment gone too far.
1. You Can Cut One in Half & End Up With Two
Planaria don’t die when you cut them. They regrow.
Slice one across the middle? The head regrows a tail. The tail regrows a head. Chop it into five pieces? Congratulations, you just made five new worms.
It’s called fission-based regeneration, and planaria are masters at it.
2. Some Planaria Can Grow Multiple Heads
In labs, scientists have created planaria with two, three, even four heads, and they all function.
One worm. Multiple brains. No thanks. Even weirder? Some planaria with extra heads still try to move in two directions at once.
3. They Have No Blood. No Lungs. No Mercy.
Planaria breathe through their skin. They have no circulatory system. They detect food using light-sensitive cells and a weird “smell” sense that tracks rot.
It works because they evolved to live in total filth and hunt anything soft and slow.
4. They’re Basically Immortal (If You’re a Scientist)
Scientists use planaria in regeneration research because they can live and regenerate for months, even after brain removal.
Some planaria have even passed memories to their clones after regeneration. Nobody knows how. It’s science. It’s terrifying.
5. They Lay Eggs in Sponge Filters, Then Disappear
When you think you’ve beaten them? They’re often just hiding.
Planaria lay tiny egg capsules in your filter sponge and wait. Once the food returns, they hatch, and the whole thing starts again.
It’s like they planned it.
Planaria Takeaway
You’re not dealing with ordinary aquarium pests. Planaria worms are tank-terrorizing, shape-shifting, clone-spawning nightmares, and they’ll outsmart you if you let them.
Keep Your Tank Safe: More Aquarium Pest & Disease Guides
Beating planaria worms is only the start, and other threats can strike just as fast. If your fish scratch or gasp, it may be freshwater ich, a parasite as relentless as planaria. In saltwater, the bristle worm divides aquarists: helpful scavenger or hidden menace?
Goldfish face their own battles with common goldfish diseases like fin rot and fungus, while bettas are prone to stress and common betta fish diseases if conditions slip. Whatever your tank issue, we’ve got you covered.
Tell Us Your Grossest Planaria Story! Did you wake up to worms on the glass? Lose shrimp overnight? Or try a “brilliant” DIY cure that backfired? We want the horror stories, the fails, and the worm-count records. Drop your planaria confession in the comments and make us laugh, cringe, or both.
I like it????????
Thanks for this. I had a wonderful population of burrowing snails, that I discovered around the time I discovered planaria in my tank!
A couple months later I noticed I cannot find any burrowing snails (though I still have rams horns).
Guess now I know why!
Hi Jon,
I’m glad this helped you out!
I have planaria in my tank with very expensive piece. Zebra. How can I kill all planaria without harming my piece and discus
Hi Paul,
My suggestions are mentioned in the guide above. Manual removal of planaria, such as using traps is guaranteed to be harmless to your fish. However trapping every last flatworm is unlikely and you will need to use it on an ongoing basis. As always, research anything that you plan on adding to your aquarium to see how it will interact with your unique setup.
Can the planaria powerder hurt my fish (flowerhorn) or stress them out?
Hi Oswaldo,
When used correctly, planaria zero is considered to be fish safe and many hobbyists, including myself, have successfully used it to rid themselves of planaria. If you are unsure, I would discuss this further with a Flowerhorn expert.
Hello Sir,
I have a bare bottomed discus tank which I keep meticulously clean. Yet I have got a white worm like pest in my aquarium. They are no more than 5mm long and as thin as a human hair. They crawl, not slide up the glass, and can become free swimming, they wriggle through the water like a small snake. I have got a video of them which I would like to send you to help me identify what they are, and how to get rid of them. This is important to me because this is a 130 litre discus breeding tank, and I see them invading the discus eggs on the breeding cone which frustrates the adult discus, and annoys the he’ll out of me.
Thank you in anticipation.
Hi Steve,
If it can wriggle through the water, it likely isn’t planaria – these things are surface huggers. It’s possible what you have is commonly referred to as a detritus worm.
I highly recommend signing up to an Online Aquarium Forum and posting your info and video there, there is no doubt that someone has experienced the same infestation and will be able to identify the pest right down to it’s scientific name.
Yeah. It’s a nematode.
I have a fish tank with a sunfish, the sunfish died, when i looked in the mouth of the sunfish I saw all of those planaria pack in the mouth so water couldn’t get to the gills, is this common with sunfish?
Hi Mary,
It sounds like this is more likely to be a parasitic infection than planaria.
Is this safe for discus tank containing rummy noses, blood fins, sterbai corys, balloon belly rams, congos, otocinclus cats, and cardinals? I’ve searched online ad nauseum for interaction with discus and came up empty. Many thanks for your help!
Hi San,
Unfortunately, I have no first hand knowledge as to how this would react with discus. While I have used it multiple times without any negative affect on my tanks, discus were never involved. If you want to put your mind at rest, you could try dosing with Panacur instead – the active ingredient, fenbendazole, will also kill hydra. There are many reports of it being safely used with discus. In fact, it’s also suggested as a treatment for de-worming discus.
Well I started a new tank with plans for a planted nano with shrimp included and a landscape to look like they are in a forest, I have 2 other planted tanks that are about 2 years old but I really put some thought into this one! Bought a few plants from a local pet store and eventually these jerks poped up on my glass, just a few here and there, but I don’t want them with my shrimps at all! I plan on removing my nirite snail and doseing tank but I am wondering how to tell if fish have planari hitchiking in them? Would they be stuck to the outside of the fish or more in the gills?
Hi Breeanna,
Planaria can slide inside the gills of fish or on the body. The surface ones should be easy enough to spot when purchasing. As for the ones hidden in the gills, this would visibly cause the fish stress. You should already avoid buying fish that look stressed.
Can you use this during cycling with a sponge filter? I have a pond snail and no where to put him but I’m not that attached.
I recently ordered some plants that came with snails, and I made a small ‘jarrarium’ for the snails. The majority of the plants are still in quarantine but I did move two into the jar after separating them out for a few weeks.
I recently noticed little wormy things that I thought were planaria until I read your post (But was positive they didn’t look like the Rhabdocoela in my main tank.)
However, their bodies are thinner than the images you show here, and their head is a circle – not a spear shape.
They also often seem to have a dark patch around their midsection which I assume is food in their gut.
Are these the brown Planaria, or something else entirely? Could they be leeches?
Tried to get good images but they’re pretty tiny: https://photos.app.goo.gl/anovg1Nf1TTzYqfi8
Hi Bill,
What an odd looking critter. To me, because of the length, it looks like a variety of detritus worm. Here’s the closest pic I could find of something similar. The good news is they are considered harmless.
https://www.myaquariumclub.com/whitish-thin-hairline-worm-on-glass-and-water-515480.html
Thank you 🙂 I’ve been really nervous about these little things. Really glad to hear it’s just a detritus worm I’m not used to.
Thank you again!
Looking at the pics they appear to be planaria not detrius worms. If they seem to just fall when you detach one from the glass they are more likely planaria but if they wiggle quickly then they are worms.
I just added api aquarium salt to my tank and i cant say its working pretty good for me.
Not sure how to add pictures yet . After a hour or two it showed me i had an infestion. I’ll upload pics when figure out how to.
Thank you for the wonderful information. Do you have any suggestions regarding possible hitchhikers on/in snails? I have had a planaria outbreak start a year ago . I’ve been using traps and I get the numbers down but have never eradicated them. Recently, they are now in 3 of my 6 tanks. Based on your above information I plan to use Planaria Zero, once acquired. The tanks contain snails which I will remove for treatment. I know most hobbyists aren’t particular about their snails, but I am. I currently keep approximately 9 different species and 17 different varieties of snails, ranging from the common Pomacea Diffusa , to more exotic such as Black Devils, multiple rabbit varieties, pagodas etc. Based on your article, I’m thinking that may be how they came in and passed between tanks. I’m thinking they hitched a ride in a shell. Do you have any suggestions on treating the snails to rid the planaria without killing the snails? I’ve already lost several and breeding has almost halted or I thought it had. Now I think the planaria ate the eggs. I’d appreciate any advice!
Hi Meg,
I know some aquarists use PraziPro (active ingredient: praziquantel) when quarantining freshwater snails before adding them to their display tank.
PraziPro can kill both Planaria and parasites. Just make sure the solution is pink before using it – if it has been frozen, say during transport, it goes clear and won’t do anything.
I have personally seen one fishkeeper successfully use PraziPro with rabbits and mystery snails, so I believe it to be safe for the larger varieties. As with any chemical you add to your tank, I highly recommend researching it further first – all tanks are different, after all.
Will planaria kill mystery snails? I just found out i have the brown planaria in one of my planted tanks. I going to assume they are in all of my tanks. I have bought mystery snails on and off over the last nine months and they have all died on me after 2 or 3 months. I have no clue why they all died very slowly. So i am wondering if it was t by e planaria.
Hi Sandy,
If you have eliminated all other causes, such as poor water quality, say your tank isn’t cycled or your water is high in ammonia (use an aquarium test kit) then it’s possible planaria are responsible for the deaths of your snails.
I cannot seem to get hold of this product.
Hi Gina,
You likely are not from the USA then. No-Planaria is another product commonly used in Europe, I believe it to uses betal nut extract. You could try that.
In the Pacific regions the product is branded “Safe-Guard Canine Dewormer for Small Dogs”.
See: https://www.amazon.com.au/dp/B000FPH2EW/ref=pe_2361882_282382012_TE_item
Just wanted to give a big thumbs up to this post and another recommendation for No-Planaria for eliminating Planaria or Hydra. I see a lot of people nuking their tanks with all sorts of meds and I believe as a hobby we should move forward by using safer and more effective methods. When people say they just nuke their tanks with dog medicine I either assume they are stubborn, misinformed or new.
Thanks for your feedback, Andrew.
I completely agree with your your thoughts. Unfortunately, dosing tanks with synthetic chemicals has become normalized in the fishkeeping hobby.
I read that increasing the temp of the tank to 35C for a few hours may work (after removing fish of course). Would you recommend this? I was worried it may kill the bio filter but I did some research and it turns out they only die at close to 47C. The only negative I can imagine is the plants not enjoying the conditions but unless someone set it this high for over a day i doubt it would affect them too much unless it was a very sensitive type.
Hi Courtney,
I have no experience using temperature to kill planaria. If you are raising the temperature this high I assume you have no fish in your tank? Another concern with raising the temperature is that you may trigger an algae bloom (often green aquarium water) that will require intervention even if you drop the temperature back.
What dosage did you use for the no planeria? I purchased and dosed but have seen no effect after two dosages and 5 days so far
Hi Brian,
I used the following:
Day 1 – add 1 spoon per 6 gallons of water in your aquarium
Day 3 – add 1 spoon per 6 gallons of water
Day 4 – perform a 20% water change
Day 10 – add 1 spoon per 6 gallons of water
Day 11 – perform a 20% water change
Can they be harmfull to humans, can they get inside me like tapeworms or something?
Hi Janez,
Having accidentally touched hydra with bare hands on more than one occasion, I can confirm from experience that these are harmless to humans.
I had a healthy, established fish tank and then I bought some amano shrimp from my LFS. Within days, I had a planaria outbreak. They were very, very small, moved quickly over the glass, and only came out at dusk or night.
I tired everything to get rid of them: removed all the live stock, changed out the water, put in a new filter, added salt, raised the temperature, replaced the substrate, cleaned the tank out with bleach. Nothing worked. When I put the tank back together, the planaria came back as well.
I then purchased and used the No Planaria product. It was hard to find. I got it from an online fish supplier for $36.00. I followed the instructions and was very conservative with the medication. It left the tank water very cloudy.
Well, my Betta got very, very sick and almost died. It took weeks for my fish to recover and he is finally doing better. That said, it is two months later and the planaria are back (or still there).
I am not going to use the No Planaria product again. I’m just going to live with the Planaria as is while continuing to keep a clean tank. So, if you plan to use No Planara, be very careful.
Hi Carri,
I really appreciate you sharing your experience. While I have been unable to replicate your process with my use of it, like with every product we add to our tanks, it makes sense that there is room for things to go wrong, especially when we all add different chemicals, substrates, foods etc. I’m glad to hear that your Betta pulled through!
I have 4 tanks going now. In one, I have Planarian and they killed my Nerite! Fortunately, I have no shrimp in that aquarium. I have another tank (3 gal) with Hydra infestation (last time I buy anything but plant cultures.
Another tank has two guppy fry, which were all we could save from Mom and the corydoras. That tank also has an expecting Platy, which is of course separated from the guppy fry.
Finally to my questions: 1) While I have no signs of infestation in the platy/guppy tank, should either hydra or planaria rear their ugly heads, is Planaria Zero likely to kill fry? 2) Somehow I suspect that sharing if nets and possibly even the liitle jars I use for water samples is a potential route of infection; should I use different nets, jars, etc. for different tanks? While I await a reply from someone, I will be buying separate implements for each tank just as a precaution.
Hi Susan,
Since Planarian are hitch-hikers, the easiest way to infest your tank is to accidentally transfer them when sharing equipment between tanks. Your decision to buy separate implements for each tank was a wise one! I have only used Planaria Zero with adult fish. Since fry are more sensitive, I do not know how they would react.
Hi! Thanks for such an in-depth article. I’m currently in the business of raising ramshorn snails – I have a multi-layered recirculating system (six 2-gal tanks first level, feed into three 10 gal tanks, feeding into 150 gal sump). I noticed today one of the top layer 2 gal tanks was infested with planaria, interestingly enough it seems to only be that tank. I have since removed snails to a quarantine tank and stopped water flow to the infected tank/emptied the water.
After watching my quarantine snails it’s clear the planaria are disturbing the snails as they withdraw once the worms touch any part of their soft body. I have tried prazipro with little success. Do you think there’s a possibility to find a secret spot in dosage using the product you suggested that could effectively kill the worms but leave my precious snails safe and sound.
Thanks in advance for any advice you can share on this tricky issue.
Hi Ivanna,
That sounds like a really tricky scenario. I’ll admit that I do not have any experience using betal nut extract at a half or weaker dose. If you wanted to experiment, you could try adding a single planaria and a snail to their own tank and monitoring what happens – if you are in this for the long term, it would be good to narrow down what works. But I do not recommend blindly testing on an entire tank. I wish I could be more help here.
Hi Ian,
Love your post and it help me alot!
I recently found the Rhabdocoela worms in my shrimp tank.
Do you think the “Benibachi Planaria Zero 20g” can kill them?
https://www.amazon.com.au/Benibachi-Planaria-Zero-20g/dp/B00E877CPW
Do you have any alternative solution for me to get rid of them?
Many Thanks,
Andy
Hi Andy,
Rhabdocoela can go away on their own if you “starve” them of food. They often explode in numbers in non-maintained tanks or where overfeeding is caused. Since they are harmless, I tend to leave them to co-exist with my tank, they help keep the tank clean!
The last planaria infestation I dosed with Panacur C also wiped out the Rhabdocoela as well. I’m unsure if Planaria zero will do the same – I used to recommend that over Panacur but it can be difficult to track down and shipment sometimes takes weeks.
I have read your article and appreciate the information on these worms. I have a newly 10gal tank I’ve set up for shrimp and I’ve noticed one of these on the glass then go down into the gravel. I’ve read through all the other comments but didn’t see a comment about adding Panacur in shrimp tank. Is it safe for shrimp?
thanks
Hi Robert,
Excellent question, from personal experience, I found Panacur C to be shrimp safe – tested it on cherry reds and amano. Other fish keepers widely report success too on aquarium forums as well.
Hello, my tank is currently done cycling with two male guppies. Can I dose Panacur while fish in the tank with life plants too?
Hi Amy,
Yes, Panacur C is can be dosed with fish in the tank.
Hello, ive recently notices these little white worms in my turtle tank. It contains a softshell turtle, a musk turtle, and 2 sliders , along with live plants and snails. Is the treatment safe for turtles? Or should i remove all live animals before treatment? Thanks
Hi Brandi,
Unfortunately, I do not have any experience with turtles – I’m purely a fish kinda guy. Can anyone with a turtle tank weigh in and help?
I added sum guppies, mollys and feeder fish and they cleaned them right up!!
Hi Brandi,
Sounds like you either had detritus worms or rhabdocoela those fish don’t eat planaria. That’s good news though, I’m glad you found a solution!
I’ve just noticed these white worms in my tank and my fish have dying and some are coming out in white spot is this down to this I’m treating the water but nothings happing do you have any suggestions on how to clear it thanks
Hi Josh,
It sounds like your fish have ich, which is not caused by planaria.
Planaria zero the best way to treat your fish tank
NO need to publish on page, this comment is just for the sake of sharing with you, this was very interesting to read. My daughter just did a bio lab experiment where they split this type of worm to make it grow two heads. I had never heard of this worm, so in “googling” it your link popped up. All new to me. As i stated this page is very interesting and informative including the comments and questions at bottom of who are dealing with these tiny critters. Since I have always appreciated viewing well kept aquariums/tanks, especially with shrimp and such, i guess it made the topic that much more intriguing. Thanks.
Hi Julie,
That experiment sounds very interesting! I think the only thing more scary than planria already are would be a two-headed version!
Thanks popping in to comment!
How about for scaleless fish? I have an axolotl. The tank has been up and running for awhile. I just had done a 75% water change and then boom a bunch of worms :/ I had gotten some new plants about a month of two ago, they came with a healthy batch of pond snails 🙁 but nothing more than that. Do you think I should just remove all decor and throw plants out and just water change a bunch? Would that help…or do I need chemical treatment? If so should I put my axolotl in a 10 gallon holding tank while I do that? I use a sponge filter so I am assuming there would also be some in there to right?
Hi Julia,
Unfortunately, I do not know a whole lot about axolotl. On the worms front, are they long and thin? A water change can often push water around the tank and send detritus worms out of hiding. Detritus worms are safe.
Whether they are detritus worms or planaria, a water change and removing decore won’t get rid of them.
Hi, can I use your blog for my academic writing?? How would you like me to cite your blog if I am allowed to do so?? Thank you very much. I find the information here quite useful.
Hi Belle,
Absolutely. If you can link back, great. Otherwise, however you see fit. My main concern is sharing good information with everyone.
Somehow internet shut down on me … so my question on Panacur C … never mind ???? there’s no easy way to get rid of them when the planted tank has nerites, fish and shrimps????
Thank you for posting this information! My tank has an aquaclear power filter, with a sponge, active carbon, and BioMax beads layer. From what you wrote, I know I should pull the carbon (and will replace it with a new one when the tank is done being treated). But, I was wondering if the sponge and/or BioMax beads should also be pulled?
Thanks again!
Hi Skratazoid,
The beneficial bacteria lives in the sponge and biomax. Ideally you would rinse the sponge off in siphoned tank water so as to keep whatever benefical bacteria is inside.
Hey I have the worms ur talking about the black ones with the triangle heads I was wondering if you know do hot water kill them. I’m gonna clean my tank but I wanna get them off the sand to and if scolding hot water kills them I can just boil some and clean the sand in it
Hi Eric, good question, I have no experience using boiling water to kill them since that would involve emptying my entire tank. I would be very surprised if they could handle boiling water.
Regarding the recent question about boiling water’s effect on planaria: I have been using hot (140-150oF) running tap water to remove them from my plastic siphon hoses and rectangular plastic fish boxes I use to put a dirty filter in to prevent spillage/drips. After using the plastic fish box to handle the filter, I often have a dozen or so planaria that have fallen from the filter element. Rinsing with water that is less than hot will not dislodge them but they let go if it gets hot enough for long enough. I rinse the hoses over a white sink and as the hoses heat up, suddenly there will be a shower of panaria coming out as it gets hot enough to dislodge them. They go down the drain, so I don’t know if they are dead or stunned.
One might use caution in heating a glass aquarium…sheets of glass can crack under uneven and drastic temperature changes.
I have 7 tanks running and several of those tanks in various stages of infestation. I have treated the worst tank with fenbendazole. Prior to treatment, I removed the H. rasboras, snails and (almost) all the cherry shrimp, then placed two 2-1/2″ to 3″ goldfish in the heavily planted tank. They grubbed and rooted around for a couple days and seemed to get almost all of the planaria. Amazing how enthusiastically they ate them. I took the goldfish out and treated the tank. I’ve only seen a couple crawling around and got a few out of the filter, and I’m due for the 48 hour retreat tomorrow morning. I’ll probably let that stand for a day or two, then start with the water changes.
Thank you for your detailed article! I remember planaria from biology class a few decades ago, but didn’t realize how dangerous they were in a tank, nor how quickly they would multiply. I very much appreciate your advice.
Hi Ed,
Thanks so much for sharing your experience on the effects of heat on planraria. Your caution of heating up a glass aquarium is also well founded.
It sounds like you are trying to overcome a big infestation. I wish you the best of luck with your battle however, I’m sure the Fenbendazole should do the trick.
By your experience, how soon is it safe to return snails into the tank post treatment? I have Ramshorn snails, Red-rimmed melania and Acuta bladder snails in there.
I’m still on the fence about using chemicals to solve the infestation. There are Zebra plecos in that tank – a fairly sensitive fish. They also go eat only after light gets turned off and I suspect the planaria are eating their food beforehand, so there is no hope of reducing population by starving them. I’m trapping the pests for now, but would be much happier with solution, that can get permanently rid of them. If anyone has any experience of using Panacur in tank with zebras, or any other Hypancistrus, please let me know.
Hi Katy,
I asked my local nerite expert. His process is 3 large water changes (50%+) adds a carbon filter and waits a day before reintroducing his nerites.
Hi Ian!
I have pet snails and I recently noticed these tiny white worms. Yesterday I saw 2 bigger ones and I confirmed that they are indeed planarians thanks to your guide. Now I am getting ready to get rid of them. As you have mentioned, the panacur C is harmful to snails…so I will take them out and put them in a quarantined tank while I treat the infected tank.
My question to you is when will it be safe for me to reintroduce the snails back into the treated tank.
Thanks in advance !
Hi Linh,
The snailkeeper at my local fish club does 3 large water changes (50%+) adds a carbon filter and waits a day before reintroducing his nerites.
Tonight I noticed an out break of these white worm looking things that were attached all over the aquarium walls. I’m not sure if they had a triangular head though as they were very small for me to see that detail. Along with this outbreak I also had an infiltration of those annoying brown snails and this all happened after adding new plants and 4 shrimp to my fish tank. I went to my local pet store and I bought new everything, new 10 gallon tank, new gravel — in this case I decided to try sand now, new filter, new ornaments, new heater, the only thing I kept the same was my tank light and I cleaned that sucker too anyway with Clorox wipes. I was so paranoid to touch those little suckers, I wasn’t sure if they were harmful to humans? I wore gloves the whole time and I put all the contaminated snail infested and worn infested items inside a trash bag and put them outside in the bin. So, are any of these worms that can come from fish tanks be bad for humans or are they harmless? Thanks in advanced. 🙂
Hi Cassie,
Generally speaking, Detritus worms and Planaria will not harm humans if they touch your skin. Even so, I personally use gloves when dealing with them.
So the actual ingredient that kills the planaria is the fenbendazole?. So is it potentially just as likely to work if I was to buy straight fendendazole?. Or any other pet dewormer containing it?. Just purchased a 35g planted cherry shrimp breeding tank for a deal that seemed too good to be true. Now we know why, got home and noticed the little buggers everywhere. Will it effect the plants in the tank?. Would it be easier to just flush the whole tank and start a new one?.
Hi Alex,
That is correct, the active ingredient is fenbendazole. Unfortunately, I have no experience using straight fenbendazole and could not tell you how to dose it.
When dosing, it shouldn’t have any impact on your plants. Whether it’s easier or not depends on your situation. If you are happy to strip the tank back and start again, then that’s the easiest and cheapest process. However, if it’s already set up, then you will need to cycle the tank again.
The Fenbendazole concentration is 22.2% in Panacur C. To match that in pure Fenbendazole, use only 22.2% of what has been recommended.
If the desired dosage for the 22.2% concentration is .1 gram/10 gallon, the pure Fenbendazole would only require 0.0222 grams/10 gallon. (0.1 x 0.222 = 0.0222)
Hi Ed,
Thank you so much for clarifying this, I really appreciate it.
I have guppies in my 10 gallon tank. I was wondering if I’m going to use panacur c, is it safe to leave the guppies in the tank or should I take them out? Also if I were to leave the guppies in the tank and I use Pana cur c would this product help to get any internal parasite out of the guppies?
Hi Chad,
The guppies should be fine. As for the internal parasite, it’s hard to say and would entirely depend on the parasite inside.
Very informative.
Thank you for giving back to the hobby you have enjoyed for so many years. It augers well for the fish keeping community.
Hi Graham,
Thank you so much for the kind words, It inspires me to keep creating these guides!
I have these inside my body. I ran into a sticker bush on side of road and ever since I have had a few different little critters. How can you get rid of them in humans? Please help
Hi Lisa,
You need to see a doctor ASAP.
I have been to doctors. No one will help me. Can u tell me what will kill planarian flatworms in a human?.
Hi Lisa,
Unfortunately I cannot. I am not qualified to provide medical advice. If what you are saying is true, it is serious and requires medical intervention.
Food grade Diatomaceous Earth kills parasites, worms and a host of un wanted buggers in the digestive system.
Lisa, I’ve read that a couple things will kill in humans.. Albendazole, Praziquantel. Usually the Dr. Will give one 400 mg. Albendazole tablet. I was infested and this did not work. I had a huge learning experience and it took awhile to figure it all out. I have used everything. Ivermectin, garlic, neem oil, castor oil, dewormer for equine BUT SAFE FOR HUMANS. RAW LEMONS WITH SEEDS.PAPAYA with some skin , fruit and mostly seeds . Cloves. I’ve had the best luck with using a combination of different ones combined. Also health food store suggestions. I’ve been to two Dr.’s 2 hospitals, ear nose and throat, and urgent care . Delusional they say. I wish! Why Dr.’s have such a hang up about treating someone for worms or parasites I do not know. They must really like to diagnose delusions incorrectly. I had my vet test because All Ballad employees were saying it’s nothing when I would bring in samples. I’ve never seen anything like it. Abingdon, Va. And because I told them about the equine dewormer, I was taken to state mental hospital. Even after I explained it’s exactly the same as Reese’s pinworm meds bought otc. Pyrantel Pamoate. I only used dosage for my weight. Didn’t matter. I have been through hell. And still dealing with it. Wish you the best of luck.
oh god
Good morning Ian,
I am very glad to have found your site and this article. Great stuff – both the information and the responses to the comments. I’m hoping you can clarify a few quick things as I hope to treat my tank today.
I have a long running 38 g, heavily planted tank with CO2. Lots of substrate, wood and plants. Not many fish, but lots of mixed neo shrimp and 2 “Zebra” snails. I had some larger shrimp (Amano and long arm), but they were apparently killed by this outbreak on Planaria.
I have noticed these little worms now and then over the years my tank was running, but always just a few. I thought they were the harmless detrius, so I let them be. I went away for 4 days and my friend overfed. I came back and there were hundreds! I vacuumed up many as they slide up the glass, but still they come. I’m ready for the treatment and will go to the Pet Store as soon as they open.
My questions please:
– The stores don’t have Planara C, but other brands with 22.2% Fenbendezol. Is this the same?
-I have 2 Zebra Snails. Should they be removed?
– If snails are to be removed, can they live in a floating bag with some thing to hold onto for a few days (for heat purposes?
Thanks again Ian. Hoping for a quick reply. Thanks again Ian.
Hi Lonny,
As another commenter pointed out, the fenbendenzole concentration in Panacur c is 22.2%, so the others may be similar. However, the non-active ingredients may be a cause for concern. I have no experience with other medications and you would need to confirm that it is the same as Panacur C.
Are they zebra nerites? Panacur is harmful to nerites.
Why not take some of the tank water out, put it in a big bowl and put your nerites in that instead? This way you can feed them, monitor them as usual.
Thanks Ian,
I took the chance and used the product Safe-Guard. Had to! It got real bad. Watching them attack and kill pregnant shrimp is nasty.
Because the stores weren’t to open until the next day, I tried a diy trap. A small plastic water bottle with pin holes in the bottom, and then food and water inside. Capped and sat on the bottom. By the morning there had to be at least 100 in there.
Did the treatment last night and this morning I only saw a few. This evening I’m seeing a bunch again. Hoping the 2nd treatment tomorrow evening will do it. After that, I’ll look back through your article and the comments.
Thanks again.
PS – now I need to go look if you have an article and Q&A for BBA!
Hi Lonny,
That sounds like a horrible situation. I can see why you made the judgement call to use an alternative dewormer. I would love to hear about how or if safe-guard works. I used to recommend a product called planaria zero, it’s essentially just betal nut powder and works amazingly well for both planaria and hydra. However, due to it being difficult to locate (it’s a japanese product) and it not always being in stock, I updated to the recommending pancur c, which is effective too.
I do have an article on black beard algae, right here:
https://fishlab.com/black-beard-algae/
Thanks Ian,
Well, it’s 48 hrs since the first dose and I just did it again. I have seen more of them little buggers today. I sure hope round 2 kills them off. I have seen no words about a 3rd round.
Good news are all fish and even the shrimp babies look to doing just fine.
Thanks again. Now off to read your BBA article. You might be the most efficient killer I’ve dealt with 🙂
All the best!
It sounds like you have quite the infestation. If I was in your shoes, and the safeguard does appear to be working, killing them off, I’d keep dosing. But I’ll be surprised if the second dose doesn’t do the job – I have witnessed a 2x dose of panacur kill outbreaks where the numbers of planaria were likely in the thousands.
Just be mindful that if all of them die at once, and you don’t remove them, then it’s possible the rotting bodies could lead to an ammonia spike.
Hi! I’m currently dosing panacur to rid my tank of planaria. Are there any particular steps I should take regarding washing/disinfecting my siphons and buckets used to clean my fish tanks to avoid spreading planaria to other tanks? Should I be concerned about contamination via cleaning equipment?
Hi Gretchen,
If you run a multi-tank setup, then it’s typically recommended to buy a set of equipment for each tank to avoid diseases spreading. For instance, each tank would have it’s own net. Despite this, siphons are often shared among tanks. If you are dealing with an outbreak then I would disinfect any shared buckets, siphons and nets etc. If you use bleach or soap, make sure you rinse it thoroughly before leaving to dry.
Hi, this article was the most helpful that i’ve found. I just saw one worm in my tank but crawled out of sight as i went to get my net so I couldn’t look for these characteristics. When I see it again, if it is Planarian, do I keep my fish in the tank when treating it?
Hi Alayna,
It’s also possible it was a detritus worm which is totally harmless. But if it’s planaria, you would treat the entire tank with the fish inside.
I have a tank with an axolotl. I’ve noticed planaria worms. There were 3 at first and i use a cup to remove them. I spotted 3 more on my axolotls food and quickly removed them. No more. Spotted a thing dangling of the axolotls gills might not be it buuuut.
What should i do. I dont want to se a canine dewormer but if i have to ….
Hi Tom, unfortunately I do not have any experience with axolotls and could not confirm that canine dewormer will work the same as it does with fish.
Hi Ian I really appreciate you posting about this subject. Does your recommended treatment harm aquatic plants? My tank is full of plants.
Hi Cynthia,
Generally speaking plants should be perfectly fine. Canine dewormer does not affect them. However, if you have especially sensitive, high-maintenance plants, it might be worth researching how it affects that species specifically.
Thanks for the reply!
Ian will this work with a 20 gal with zebra danios, Red eye tetras, mollies, and fish of these sorts? I’m sure there planaria they move on the glass I find them at the top of the glass tank by the water line. I see white ones mostly but have seen some black ones slivering on the glass my water numbers are great and ammonia is great.. I’m grossed out how did they get in my tank had the tank 2 yrs now.
I’m also doing antibiotics in the tank i have a sick red eye tetra. Twitching and laying on its side struggling been that way for 8 days still hanging in there hoping it get better.
Hi Lisa,
Yes, this method is fish safe, myself and many others have used this in community tanks without any issues.
When you say “great” what are your exact measurements of Ammonia, nitrite, nitrate, pH and water temperature, how long each day do you leave the light on and how often do you do a water change?
I have used this treatment twice. Thought problem was cleared up but I now have lots of little white worms floating round the water. Too small to see if these have an arrow head. I am assuming that as I had a definite worm in there last week that first lot of treatment didn’t work. I have now repeated the treatment and waitin to do the 2nd dose. Worms still look wiggly and alive. Tank has cherry shrimp and 2 ghost shrimp. Planted 25L tank. Using the 500ml per 1g packet as no scales to measure. I am also very new to shrimp keeping. Need advice please ????
Hi Victoria,
Pull out your phone and take a photo and zoom in. You want to make sure you are using the correct treatment for what is actually in your tank.
They so small. Almost like tiny hairs. They not as big as the definitie planaria I managed to get a photo of last week. These are really tiny. Still moving on glass today. Haven’t seen the 2 large planarians I originally saw. Possible these could be diff ones. I have included a link to a video I managed to zoom into as phone was finding it difficult to zoom in as they so small. Hope it helps.
https://youtu.be/rU1YDX0p5_Q
Hi Victoria,
Unfortunately, that video isn’t going to help, they could be rhabdocoela or any flatworm. You’ll have to use your best judgement here.
Hello Ian! First thank you for your blog, I’m less than a year into the hobby, and your blog is one of the few knowledgeable sources that helped me a lot.
I wish to ask you something, sorry this will be long, but maybe it will be useful to someone out there sharing my concern.
I am worried I have Planaria feeding on the detritus, and my ramshorn snails population was drastically reduced, however I did redecorate my plants and gotten rid of the bulkiness and favorable setting for snails to multiply, so I can’t tell if Planaria was the culprit.
I think I have Rhabdocoela in my nano tank, but I am still not sure yet. I like to tell myself they are not Planaria, because they are very small about 2mm and hiding in subtrate still. I saw them a couple of weeks ago. I do have however some detritus that appear only at water change but get eaten by the guppies, nothing alarming or signaling outbreak.
For now I cannot distinguish the 2 types of flatworms yet. I do know though that a couple of months ago I had Planaria (arrow head) I only saw 1 and it was big! I made a mistake of squishing it (with a sitck lol) because I had no clue what it was at that moment, and I panicked. After reading your blog and contacting my fish supplier, I used a dewormer and they were no longer visible. I had to repeat the procedure twice actually because I saw a tiny flatworm and I assumed it was Planaria again.
So fast forwarding till now, my nanotank has a batch of 15 endler guppy fry that are about 4 days old, and I do see the flatworms in the subtrate. I can see them on the perimeters of the tank inside the substrate. I can count about 3 or 5 if I am really focused on one side. They are visible on the side that is facing the wall (the side with most shade).
The mommy endler guppy didn’t make it unfortunately, and now I am left with baby fries with 2 ottocinclus, 1 endler male guppy, 4 ember tetra, and 1 cherry shrimp, and a couple of ramshorn. I don’t wish to move my fry because this tank is cycled since late summer and it is very stable.
So my question is since I can’t tell if it’s Planaria or not, should I be too concerned for now? Will they hurt my fry? I saw in your comments that dewormer might be too harsh for fry so I am going to skip it if for now, but I am worried my fry will be hurt.
If I wanted to gravel vac, how can I make sure my equipments are 100% clean and disinfected? I never gravel vac my nano tank, I do about a 50% water change every week, and change my filter cartridge every 4-6weeks. Honestly I never gravel vac-ed especially after learning there is something called planaria, detritus, and stuff like that, I hate to get some of them stuck in my cleaning tubes or thriving in my bathroom sink or toilet! Also we live in apartment, it would have been easier to dispose in garden.
Thank you in advance!
Hi Marie-Anne,
Thank you for the detailed write up. Planaria are most harmful to snails and inverts – things that live on the surfaces of your tank. If they are Rhabdocoela then they are absolutely harmless.
Gravel vaccing is highly recommended – this sucks out uneaten fish food and poop that detritus worms and other hitchhikers feed on. If you are going to share between tanks, you should wash the gravel vac.
Hello,
for like a month we have planaria at our tank at work. there also live lots of shrimps and a turtle. because of the turtle, i dont know if i could use panacur. thats why i keep catching lots of planaria with a trap but i know they wont disappear completely this way. do you know anything about turtles with planaria?
at home i got a 25l nano cube. its very new, like 3 weeks old and one week ago i found little white worms. because of our planaria problem at work, i was shocked and went to get panacur directly. ive read on the internet i should put 1ml panacur on 1 liter tank water. then after 10 days, change 50% of the water and put panacur again for the 50% water.
i got one pill 250mg panacur at the vet. you only get this at the vet here in germany and some vets wont even give it to you. ive put the 250mg pill into 250ml water already for easier measuring and now i dont have any left for the second time. everyone says you need to do everything again after 10 days because of the new eggs that hatch. but now my tank is pretty new and i dont think the planaria would have been able to lay any eggs already. do i still need to redo everything?
today, a week after putting panacur, i took a closer look at the worms and now im not even sure if its planaria. ive read that planaria without that triangular head do exist. i hope its ok to post a link to a picture here.
there is soil in the tank and everywhere they say soil “sucks” the medication in and it takes longer for it to work and get rid of it. i didnt even get to put any animals beside some little snails that survive panacur in. do you know how long it would take to get the medication out of the tank again so the snail i would like to put in wont die? does it really take months or are there any ways to clean everything faster?
Hi Ren,
Unfortuantely, I have no experience with turtles and would not be comfortable giving advice here. The good news here is that those look like they are Rhabdocoela, which are considered harmless yet may explode in numbers if they have the appropriate food source also, certain breeds appear to be immune to fenbendazole. Activated carbon and a few water changes will see the tank become snail safe in no time.
I’m wondering if panacur will kill plants. My shrimp are in a heavily planted tank.
Thx
Hi Andrew,
Good question. Panacur is considered plant safe. However, if you stock particularly sensitive plants you may want to do further research.
Thank you for the Advice on planarian. Do you have a recommendation on how to decontaminate snails before adding them back into a tank? I keep about 12 different varieties of snails including multiple types of Tylomelania. White Planarian are reeking havoc on them and my bivalves. I will need to remove 40 or so snails and bivalves from the Aquarium to treat with dewormer. My concern is planarian hiding out on the removed snails and bivalves, thus reinfecting the aquarium upon return. Any ideas?
Hi BB,
Good question, short of putting them in a quarantine tank and monitoring really closely (then shifting them to *another* quarentine tank and repeat, I don’t really have a good solution with this.
Thank you for the valuable information! I’m asking if this will kill planaria eggs in a few days also? Or is there another treatment that needs to be done later for this, besides the two treatments a couple days apart.
Hi Connie,
Good question, my experience and from the other comments left here, the two treatments are typically enough.
Planaria do not alarm me. Most fish, except strict vegetarians, will eat them. So will dwarf African frogs and many kinds of predatory shrimp. I have taken apart tanks that have an undergravel filter and there are planaria on the bottom of the filter. They probably perform a useful function there, eating excess nematodes and various kinds of dead plant and animal matter. They are not “attack worms” by any means. There is no need for chemical treatment to get rid of them. This article is an advertisement and I expect this comment to be deleted, but I will not be coming back here anyway. I am a zoologist and I tell you that diversity of animals and plants is important in your aquarium. If you have massive amounts of planaria, you just need to get a few guppies, for Pete’s sake. If you maintain an aquarium reasonably well, you will not see them. The video of planarians (which is an accepted plural) crawling all over the aquarium is staged. They will multiply like that if they are given a tank to themselves and food. Put some fish in there, and they are a feast.
Appreciate this, and your zoology background. We agree planaria are often harmless detritivores in balanced tanks, and many fish will opportunistically eat them. The caution is for edge cases, like shrimp breeding tanks, fry grow-outs, or heavily fed nano setups where planaria can boom and pick at vulnerable inverts or eggs. Our goal is not to push chemicals, but to explain causes and choices. Non-chemical steps first, and meds only when a keeper’s goals make it necessary.