We had the same experience in our 180gal as Wetfish. We raised well over a hundred Berghia from a start of 3 & have passed them all out after they ate all of our aiptasias. We got them in March, and by mid-May, there was not a single aiptasia left.
Joe's Juice does not work at all - it kills the target anemone, but in the process, it forces it to clone, leaving you with 5-10 little tiny ones that then grow up to be big ones. I did some experiments where I nuked aiptasias that were growing on the side of my tank where I could see them, and sure enough, nuking them with Joe's Juice just made them all clone. Bad stuff.
The bergies are the way to go. The only thing you should do is catch them when they've eaten all your aiptasias & pass them along so they don't starve - they only eat aiptasias and nothing else. If wetfish has given away all of his, you can order them online from Inland Aquatics, which is where we got our original 3. They were very responsible, and they shipped just fine. The company only deals in captive propagated marine life, so they're a good business to support. We didn't need 3, though - 1 or 2 would have worked just fine. The key is to keep them in a small tank - a 10 gal QT would work great. Then rotate your aiptasia-covered rocks thru. Berghia are nocturnal, so you've got a much better chance of seeing them come out to feed in a small tank. Plus, this way they're safer from power heads. They are really fascinating to watch & totally cool looking! Given that there's basically no other species of nudibranch that you can keep in captivity without killing, they're really fun to have. I highly recommend them, and if we ever have an aiptasia problem again, I'll order another one from Inland. I actually miss the little guys!
