The only thing that I found that works with no side effects at all are Berghia nudibranchs. Like someone else mentioned, they are not cheap...about $10 - $15 each for a 1/2" long nudi and you'd most likely need at least a couple depending on how big your tank is and how much of an infestation you have. The Klein's butterfly fish is another great weapon to use...they are an absolute aiptasia eating machine but unfortunately not 100% reef-safe. Aiptasia X (or whatever other aiptasia killing chemical of choice) works but as some other's have mentioned it seems like it causes the parent aiptasia to spew babies just before they die so instead of 1 large pest you have a dozen (or more) baby pests which is worse! I have tried all of these methods and I greatly favor natural predation over adding chemicals to my water that could possibly screw up my water chemistry. Honestly if you can spare the expense the Berghia are worth their weight in gold and WILL eradicate all aiptasia in your tank and if you don't have any predators that will eat their egg's they will also breed and have babies. The only downside is they ONLY eat aiptasia and once they are gone the Berghia no longer have a food source in your tank and will starve and eventually die so it's best to sell/give them to another reefer after they have finished their job in your tank so they can help someone else. The Klein's will also completely rid your tank of aiptasia but they will also nibble on some of your corals (mine had an Acan he liked particularly well) so it's more of if can you accept some minor coral losses as payment for ridding your tank of the vermin decision. Hope this helps...I have some new aiptasia myself and have already contacted my LFS about ordering me some Berghia nudi's :bigsmile: .
