I have 4 pepperment shrimp in the 29 and they never even touch the aiptasia, and its starting to really spread. I even starved the tank for a week and they wouldnt eat them, so i bought a bottle of Aiptasia Control. i was careful and followed the directions, but i still got some on a few zoo polyps. If a few polyps die off they will be acceptable losses to get rid of the aiptasia.