Almost all zoo's can cause problems. They are best cut outside of the tank. I have some gold ones I ripped off some rock and smashed up some trying to get them off. It nearly killed all my caps, but fortunately I caught it in time and did a large water change and added carbon. All is well now and the caps gew back fine. They seemed to be the only coral effected. IMO it is best to cut and frag all corals outside of the tank if possible and rinse well in SW before placement back in the tank.