Over the past few weeks i've noticed 2 of my acros and now my blue tort are decaying. I've tested my water several times and all is clear. Tested for nitrates, ammonia, ph, calcium, alk. and phosphates. And some of the other SPS, mille and monti cap, are doing great. My girlgreind got a chocolate chip star fish for the tank and said the guy at the LFS claimed it to be reef safe. But i've had to pull him off those corals several times. Is he eating them just because that's what he does or because they're already sick. I've also seen a sally light foot crab pick at it before, but i don't know if he's eating them. Also, i've been battling a nasty diatom and long hair algae outbreak but that nearlly under control. Does anyone know what's going on?