What Is Planaria?

First, let us talk about what we are dealing with. Planaria are small, flat-bodied worms, usually white or brownish, with that telltale triangle-shaped head that makes them look like they are up to no good. They do not swim so much as glide around, and you will often spot them crawling along the walls of your tank, or even worse, lurking near your shrimp on the substrate. They sneak into tanks through plants, live food, or even from your local fish store’s less-than-perfect stock.

They are not much to look at, but planaria have an odd little trick up their sleeve—they can regenerate. Yep, you heard me right. Cut one in half, and instead of getting rid of it, you will end up with two of them. Not a fun experiment, trust me. They reproduce asexually, meaning they can fill up your tank in no time if you are not careful.

How to Spot Them

• Flat, little bodies with that signature triangle head
• They slide along tank surfaces, no swimming involved
• Found on the glass or the substrate, usually in clusters

Now that you know what they look like, let us talk about why they are more than just a creepy tank decoration.

Are Planaria Dangerous to Shrimp?

This is where it gets real. Planaria might seem harmless at first, but they are opportunistic feeders, which means they will prey on whatever is weak or vulnerable. In my years of shrimp keeping, I have seen planaria go after shrimp fry (the baby shrimp) and even molting shrimp, which are already in a delicate state as they shed their exoskeleton. I cannot tell you how many times I have had to intervene when one of these flatworms tried to snack on one of my prized shrimp.

While adult shrimp can usually hold their own, the smaller or molting ones are in real danger if planaria are in the tank. You do not want to take that risk.

The Big Risks

• Shrimp Fry: These little guys are easy targets for planaria. Soft bodies, small size, you can see how that ends.
• Molting Shrimp: When shrimp shed their shell, they are soft and vulnerable, which makes them a prime target.
• Infestation Growth: Planaria reproduce quickly, so if you are not on top of it, they will outnumber your shrimp before you know it.

Now that we know the enemy, let us talk about the battle plan. There are a few ways to handle planaria, and I have tried them all. Here are the methods that worked for me.

How Can You Remove Planaria from Your Tank?

Planaria removal is not one-size-fits-all, but depending on how bad the situation is, you have options. Let us start with the basics and work our way up.

1. Mechanical Removal

If you catch planaria early, you can literally suck them out of the tank. It is not glamorous, but hey, it works.

• Turkey Baster Method: This is my go-to for spot-checking. If you see a few planaria hanging around, grab a turkey baster and suck them up. It is surprisingly satisfying.
• Gravel Vacuuming: Planaria like to hang out in the substrate, so when you do water changes, focus on vacuuming the gravel. You will pull up a bunch of them without even trying. Just remember to clean your vacuum afterward so you do not spread them.

Mechanical removal is great for small infestations, but if you have a full-on planaria party going on, you will need to level up.

2. Planaria Traps

Next up, traps. Trapping planaria is a simple and effective way to reduce their numbers without putting any chemicals into your tank.

• DIY Trap: I have made traps using small containers or old film canisters. Poke a few holes in the sides (small enough so only the planaria can squeeze through) and toss some bait inside—shrimp food works wonders. Sink the trap in your tank, and come back in a few hours to collect the worms.
• Store-Bought Traps: If DIY is not your thing, you can buy pre-made planaria traps online. These work in the same way, but they are a little more user-friendly.

This method will help get rid of a lot of planaria over time, but you might still need to bring out the big guns.

3. Chemical Treatments

Now, I know what you are thinking—chemicals sound risky. But, there are shrimp-safe treatments that can get the job done without harming your tank’s ecosystem. I have used a couple, and they work like a charm.

Fenbendazole

This is an antiparasitic treatment that works wonders for planaria. It is shrimp-safe when used correctly, and it has been my go-to for serious infestations.

• Dosage: Add 0.1 grams of fenbendazole per 10 gallons of water. It is important not to overdo it.
• Duration: Let it sit for about 24 hours, then do a water change to clear out the residue.

Fenbendazole works by starving planaria—pretty grim for them, but it gets the job done without hurting your shrimp. Just be careful with snails. Some species can react poorly to this treatment.

No Planaria

This product is an absolute lifesaver for shrimp tanks. I have used No Planaria in a few tanks now, and it is fast, effective, and shrimp-safe.

• Day 1: Add one scoop per 10 gallons of water.
• Day 2 & 3: Repeat the same dosage.
• Watch and Wait: By the third day, planaria will start to disappear. It is that easy.

No Planaria is a great option if you want to avoid the stress of handling chemicals. It is all-natural, which makes it a solid choice for keeping your tank safe while getting rid of planaria for good.

4. Natural Predators

If you are looking for a more natural approach, certain critters love to snack on planaria. While this option works, it can be a bit hit-or-miss depending on what else is in your tank.

• Assassin Snails: These guys are my favorite for pest control. They hunt down planaria like it is their job (because it is).
• Fish Predators: Fish like bettas or gouramis will eat planaria, but they can be a little too aggressive for a shrimp tank. Only go this route if you have a mixed tank where shrimp are not the main attraction.

5. How Can You Prevent Future Infestations?

Once you have dealt with planaria, you will want to make sure they do not come back. Here are a few tips that have worked for me:

• Do Not Overfeed: Excess food fuels planaria growth. Feed your shrimp sparingly and remove uneaten food to keep your tank clean.
• Regular Water Changes: Stay on top of tank maintenance. Regular water changes, substrate cleaning, and filter maintenance will help prevent planaria from getting comfortable.
• Quarantine New Additions: Planaria often hitch a ride on new plants or livestock. Quarantining anything new before adding it to your tank will help keep your setup pest-free.