How to Get Rid of Planaria Flatworms in Fish Tank?

Does getting rid of planaria worms in your aquarium seem like an excruciating task?

You’ve been an aquarist for a while and have spotted white flat worm-like creatures crawling on the tank glass—not one or two that you can dismiss—but hundreds of unsightly white worms, bravely cruising the glass aquarium. 

Sometimes, the worms aren’t necessarily white, but brown or black—with a distinguishing triangular head. 

You’re not naive, though. 

You know that if you keep fish, they’re pretty harmless.

However, you know somebody has to implement a process to eliminate the planaria flatworms or pound the pavement to reduce the infestation. Otherwise, it might pose a hazard to invertebrates like crabs, shrimp, or snails in your aquarium.

But it can’t be somebody else. You’re the one taking care of your aquarium.

You start to wonder: how are you supposed to remove planaria without affecting the inhabitants of your aquarium?

You’d think it’s impossible, but it’s not. You only have to be a little sneaky.

Cut Back on Feeding to Get Rid of Planaria

When you see white worms in your tank, it’s a sure sign that you’re overfeeding your fish or shrimp.

Planaria always thrive on leftovers.

What makes it difficult to eliminate flatworms is that they are asexual so getting rid of them while they have something to eat is nearly impossible.

The initial step to eliminating planaria in your aquarium is to reduce feeding. If your fish or shrimp fails to eat all the food, siphon the leftovers immediately.

When there’s no leftovers, the chances of a new planaria infestation lowers to zero while the current one starts to starve, which helps control a flatworm infestation.

What’s more, cutting back on feeds improves the overall health of your aquarium because excess food causes ammonia spikes to dangerous levels.

Also read: How to Get Rid of White Worms in an Aquarium

Use Planaria Worm Trap to Control the Parasites

It’s possible to collect the voracious planaria flatworms manually.

However, such a method is ineffective because a huge population of worms hide inside the substrate, plants, rocks, and even crevices.

A planaria trap is more effective. It works like a weir—using bait like a few frozen mosquito larvae, tiny pieces of meat, or a very high protein food to catch the planarian. You then place the trap in the aquarium to trap worms.

You can then collect the trapped worms and dispose of them. However, don’t just flush the flatworms in the toilet because some planaria won’t disappear for good. Soak them in boiling water to kill them first.

Using more bait, repeat the process as often as necessary to keep the planarian population under control.

However, eliminating all planaria using the trap is difficult because it doesn’t affect the eggs.

Employ Predation—Use Certain Species of Fish or Shrimp to Get Rid of Planaria

Placing specific species of fish or shrimp in your aquarium can naturally predate planaria.

Some fish species that eat planaria include:

  • Zebra loach (Yunnanilus cruciatus)
  • The Red Spotted Goby (Rhinogobius rubromaculatus)
  • Springers damsel (Chrysiptera springeri)
  • Velvet nudibranchs (Chelidonura varians)
  • Freshwater Angelfish
  • Tiger Barbs
  • Guppies
  • Goldfish
  • Mollies

These fish species naturally hunt and eat planaria. The Springers damsel aren’t overly aggressive like other damsels and have quite an appetite for flatworms. They’ll help keep the population explosion under control.

On the flip side, the Velvet nudibranchs predate only on Convolutriloba species of flatworm but will mow them down.

Since they are small and motile, this fish species will reach places you cannot with a siphon.

However, they are omnivores, and once all flatworms are consumed, the nudibranchs will most likely die. 

Alternatively, shrimp species like Macrobrachium peguensis hunt for planaria. 

Whichever natural predator you choose, your housing condition must be appropriate depending on the individual species and the inhabitants of your aquarium. 

For example, the socialization of dwarf fish isn’t possible with some of the above species because they can easily be preyed on.

As with the trap method, predators only keep the population of flatworms in check—complete eradication isn’t possible because most flatworms hide in the substrate to keep breeding.

Use Deworming Agent Treatments in Your Tank

Using deworming agents to treat your aquarium is a promising method to eliminate the triangular head worms.

Deworming agents like Flubenol or Panacur can get you a free-from-planaria tank again.

Both treatments are prescription drugs that you can get from a nearby veterinarian.

Flubenol contains the active substance flubendazole, while Panacur contains fenbendazole, whose action modes are similar.

The drugs disrupt the metabolism and digestive system of planaria, which makes them starve and eventually die. 

Unfortunately, deworming agents are harmless to planarian eggs. For that reason, repeat the medication after two weeks to kill newly hatched flatworms.

While highly effective in treating your aquarium of flatworms, deworming agents might be harmful to the ecosystem of your tanks. For instance:

  • Deworming agents aren’t a go-to option when you keep snails in your tank (it kills them all)
  • The active substance of these deworming agents remains in the substrate for several months. Returning snails to the aquarium during that period is still dangerous.
  • Overdose of Panacur can lead to deformities or reproduction disorders in shrimp

Chemically Treat Your Aquarium 

You may want to resort to chemical treatment if a coral colony—whether a newly acquired or established specimen—has a flatworm infestation.

Plenty of chemical treatments out there can eliminate any planaria worm in the tank. They include products like:

  • No Planaria Control in 72 Hours
  • Planaria Zero
  • Panacur Suspension 10% for dogs

The best practice with chemical treatment is to know how much water you have in your aquarium to determine the correct dose. 

Many people think they know—they assume the capacity that substrate, filters, driftwood, plant, stones, decoration, and coral take in an aquarium—then they end up overdosing their aquarium.

Before administering any dosage to your aquarium, know the exact amount of water you have.

What’s more, know that chemical treatment can kill shrimp, snails, crabs, or other invertebrates. Find where to put them before and during tank treatment.

That said, let’s say you choose No Planaria Control in 72 Hours product. What’s the correct usage?

Here’s is a step-by-step guide:

  1. Remove snails in the aquarium (if there are any)
  2. Detach the carbon filter to prevent obstruction of the chemical’s action
  3. Aerate your fish tank
  4. Add the product
  • On day one, add one spoon per 13 gallons (50 liters)
  • On day two, add ½ a spoon
  • On day three, add ¼ a spoon
  1. On day four, carry out a 40-50% water change
  2. Return the carbon filter
  3. On day 7, execute a 20% water change
  4. Siphon your tank to remove all the dead worms to prevent ammonia spikes.

During the first three days of treatment, avoid feeding your shrimp to prevent further contamination of the substrate.

Reevaluate Your Aquarium Cleaning and Water-Change Routine

To prevent a future flatworm infestation, reconsider your aquarium cleaning routine.

Regular cleaning is a hassle but you must siphon the bottom of your aquarium weekly when you’re changing the water to prevent excessive food build-up.

However, that doesn’t mean you have to clean all the substrate at once.

You can divide your aquarium into sections and just choose to siphon one with each water change. Plus, dividing the tank into sections will prevent stirring too much gunk that can lead even to more ammonia spikes.

Also read: How Often to Change Aquarium Water

Eliminating Flatworms in Your Aquarium Doesn’t Have to Be Impossible

It can and should be the opposite.

If you practice proper aquarium acclimation, observe your aquatic life for changes, set optimal aquarium water conditions, have the right aquarium, and follow the correct procedure—the good news is:

Eliminating every flatworm in your tank without harming any of the aquarium inhabitants is possible. You only have to understand the correct procedure. 

The best part?

You can prevent future infestation of flatworm by:

  • Feeding the inhabitants of your aquarium less 
  • Cleaning your tank systematically.
  • Taking caution about what you add to your aquarium. For instance:
  • Buy substrates and plants from trusted sellers
  • Clean, rinse, and boil sand, soil, or gravel before adding them to the tank

You may also want to read the following articles about your aquarium: