A few years ago I had a sizable aiptasia outbreak from a piece of live rock I put in my fuge. I added 3 peppermints to my 240, and within 6-8 months all traces of aitasia where gone. I never saw them actively eating, but I would notice missing tenticles from the larger colonies. I didn't want to add too many, like others have said they will steal food from corals, I figured add less, wait longer. Seems to be less dangerous to me, just in case they develop a taste for corals. I had plenty of aiptasia food to go around.