Most corals react differently around some coral , I think it's easier to find out which ones are harmful. Alot of times you just needto observe the coral in the night to get ts full size or it's sweepers. Alot of times Size will be a factor especially in coral that doesn't frag well so if you don't see yourself fragging it probably should leave enough room for a full grown specimen. I know there alot of different kinds of chemical warfare that happens with sps so might be good to specify what kind of corals your thinking of
. Read up on the coral you plan to purchase before you buy
I've bought some bad ass pieces I shouldn't have lots of times lol