I have had mine for over two years in my reef without any problems. I have a large tank w/ lots of LR and the CB just cruises all day picking at everything to see if its something it can eat. Rocks, sand, snail shells, and even some of the corals. Its what they do. If theres not enough space and rock, ect. to spread out the searching area then they will pick the same corals more often to maybe a point to where it bothers the corals too much. But I never seen it eat corals.