Worms / Snails in the tank

Question
Hi Chip,

I have a 30litre Bi-orb heated tank with tetras, loaches and catfish.  The tank has been running for a year without any problems.  No new fish have been introduced.

Recently, a number of small creatures which look like flat snails. have appeared in the tank.  Cleaning (washing, complete change of water, change of filter) hasn't removed them.

I noticed that the creatures do not have a hard shell.  They are simply small worms which move amount at various depths in the tank, in a coiled up manner.  Occasionally, they uncoil, and head to the surface, and simply hang in the water with the head (?) at the surface, and the rest of the body straight down.

They appear to be breeding, as there are about 50 in the tank of various sizes.

I had been feeding the fish dried blood worms, but have since stopped this in case it was related.

Any idea what they might be, and how to get rid of them?

Thanks
Dermot

Answer
Hi Dermot, I am pretty sure this sounds like Planaria which are flat worms. They do not harm your fish but they are usually found in tanks with too much gravel that has leftover food in it and that is what is bad for your fish.                                        Here are my recommendations:

1. Clean Your Aquarium. In particular you should clean your gravel with a Gravel Washer.

2. Add Aquarium Salt to your aquarium up to a maximum of 1 Tablespoon for each 5 gallons of water in your aquarium.

3. Don't Over React. Clean your gravel every day with the Gravel Washer. When you've removed 20 of the water, stop and top your aquarium back up with tap water from the faucet. Repeat this procedure every day.

4. It may take several days of gravel washing to get your gravel really clean. When it is finally really clean, begin removing gravel, until it is at most 1/4" deep.

5. Add Quick Cure. Each day after you clean your aquarium and wash the gravel, treat the water with 1 drop of Quick Cure for each gallon of water in your aquarium. You can also replace the Aquarium Salt that you removed, which would be 1 Tablespoon in the 5 gallons of water.

6. Small fish such as baby mollies might eat the planaria. I would try adding a few small fish to see if they will eat the planaria.

Repeat steps 1 to 6 listed above, until you don't see the worms any more. This procedure will take several days and require quite a bit of your elbow-grease, but it's the safest method for the rest of the fish in your aquarium.

I hope my comments help you. If you have a follow-up question, please send it to me. Good luck with your fish.