Cleaning out my filter I found 1/4" long and smaller red worms in my filter media floss and sponges... what are these? I haven't seen them any where in my tank only the filter. I have a 60x18x18 tank with sand bottom and Rena xp4 filter. stock list 2 river cooter turtles, 2 crawfish my kids rescued from the pot on mothers day, 60 grass or ghost shrimp caught from local bayou" five sun perch all 1" and 3 bass 1", 2 blue catfish all of this comes from bayou by house..