I have an 8" red claw in with my large SA/CA cichlids. He has been there since he was about 3" with no problems. He has many hiding spots that the other fish cant get into and he has grown like a weed while cleaning up the mess left by the large (and notoriously messy) cichlids. My tank has never been cleaner and I rarely vacuum it now. Maybe every 6 months or so (still regular water changes though).