i would also tend to agree that this is not a foe but a friend. I have had in the past some worms in my external filter gunk, but these were blood worms from live food. I however would also be cautious, as one worm can grow to many quickly. Usually other fish would each a tasty morsal like that, so if you have seen and caught 2, I would say you might have more hidding. If you would have corys I would say leave them as they catch them, if not well generally my theory for all my tanks is - remove anything that should not be there or that you are unsure of, this just to be on the safe side. Cheers jk :thumbup: