Its a 60 gallon cube, about 6 months old. No new live rock, I have a cleaner shrimp and 2 emerald crabs. A blue chromis, helfrichi firefish, another clown about half its size, and a cardinal. Im assuming it was the powerhead because hes always around them because thats where the extra food floats around at when I feed them. I also just covered the powerhead. About the the clowns fins. He has absolutely no pelvic fins now. Just two little stubs. So no chance on growing back? :[