So - I tried peppermint shrimp -no effect. I tried hot (boiling RODI) - no effect. I bought a file fish - no effect. I bought a copper band - no effect. I bit the bullet and ordered 11 berghia nudibranchs. They were maybe 1/2 inch long. I put them in the tank - never to be seen again - and I thought - hmmm... I talked to the person who sold them to me - they said - they are mostly nocturnal - once they start to lay eggs -you will have a lot of babies - and you will see the aiptasia slowly dying. At about 2 weeks - I noticed - several of them didn't look so good - i.e. somewhat shriveled - by 4 weeks 99 percent were 'gone'. I have yet to see a nudibranch that I could 'rehome'.....