I have one 5" in my tank with sps, elegance, acans, zoas, and a crocea clam. It doesn't bother any of those things. It loves nori and just about any food I throw in. I believe the trick is to get them very small. I bought mine about 2" from Diver's Den and she started eating flakes on the first day. Have added new corals and she doesn't even touch them, really recommend if you're not too risk averse.