If you keep a healthy reef, you will eventually have to frag or the corals will sting each other and do it for you as they compete for space. A stung coral skeleton invites algae growth as well. I hate to frag myself, and like big, healthy looking colonies, but my advice would be to remove a chunk of it and sell it, keep it in another part of your tank, or trade/give it away. The BGM is always in demand.