ive used it in a full mixed reef with inverts and that was what i was worried about but to my surprise it hurt nothing.....i didnt have any sps mayby be some hardy stuff like pocci,monti and birds:P
should also say ive only used it once and i doubt i would do it again as i believe there are other ways to treat but at the time it worked for me and the tank i used it on so gl
cheers