I need some help....I have some kind of flatworm in my tank. It's not eating or bugging any of my corals. I got scared at first thinking I'd lose my SPS. These things are feeding mainly on my coralline algae on the rocks. Right when my tank is doing good and these things appear. Whats a good fish or other animals that might eat these things? They are brown and and anywhere from 1/16 to 1/8" long. I'll try to post a pic. Please help.... Thanks Mikee68