I don't think there is such a thing as a totally "reef safe" Centropyge. I have read that if there is an abundance of algae in your tank that it may keep the nipping at bay. I have also read that trying lettuce or algae sheets could help. I had a coral beauty angelfish that liked to nip or sample my corals. It did not do any serious damage, but it really frustrated me watching it investigate the corals with its mouth. This is something that you probably have to tolerate if you are interested in keeping this kind of angelfish.