I think you need to get your CBB to eat other foods. IMHO, when the fish start eating the corals in the tanks they are missing something in their diet. Get some black worms for the CBB, and keep him well fed. I have a CBB and a couple of Dwarf Angels in my reef tanks with plenty of corals and clams and they never bother them. I believe it is because they are well fed. Then again, some fish are just jerks.