Found a good post on r/c about getting rid of aiptasia.Just get a large syringe and a cup of boiling water,stickem and watch-em melt .I had about 50 of them in my 30g because when i was a new-be i thought they looked cool until they took over the tank.
well three cups of water & a hour later can't find one just gooey remains.worked for me and kinda fun watching your problem melt away.

well three cups of water & a hour later can't find one just gooey remains.worked for me and kinda fun watching your problem melt away.