I just found an aiptasia on a rock where my sea star is currently hiding I think my best bet is to take the rock out and let it sit in the sun for a few weeks. My brother who has a 150 gallon fish only tank just got over the worst infestation of these pests (a year and a half battle) it was so bad he almost got rid of his tank for good. He lost all of his mushrooms and almost a leather coral. Needless to say im not taking any chances on this.