I've got worms!!!

[lanoit]

Question - when cleaning my tank today I noticed that there were hundreds of tiny hair-like worms in the water when I stirred up the gravel. Most were dead but I know that some were alive because they were wriggling around. I also saw that a couple of my fish were eating them.

Are worms in a tank normal? They're not going to hurt my fish are they?

Thanks!

 

[Leopardess]

They're fine and so are your fish. Those were most likely a little thing called planaria or it could be a roundworm of some sort. Neither are harmful to you or your fish. In small numbers, they indicate a diverse ecosystem - when they are as plentiful as it seems in your case, they indicate poor water quality and/or too much waste in the system (ie filters and substrate). Frequent water changes, gravel vacing, and reduction in over feeding will eliminate them, or at least greatly reduce their numbers.

Anytime you see a free swimming worm, don't panic - anything that is dangerous to your fish needs a host