IMHO the BEST way to deal with Aiptasia is Berghias (although they don't fix the problem overnight). I had a very major problem in my 135 - started out with a couple and over the course of about 6 months ended up with literally hundreds of them everywhere. I tried Peppermints (didn't work - they wouldn't touch the bigger ones), Joe's Juice, Lemon Juice, Kalk Paste, etc. The problem with all these is you always leave some behind to reproduce.

Finally I added 4 Berghias. I didn't see them for about 3 months, and thought they had died or become fish food. Then I started to see the odd one. About a month later, I started to see more and more. At their peak, I had probably about 100 visible during the night. It was really neat to see the Aiptasia disappear a little more every night. They found their way into my sump, refugium, overflows, everywhere. Within 1 month of their becoming visible, every trace of Aiptasia was gone.

The good part about them is there is no place for the Aiptasia to hide from them - they will find it in every crevise. One of the best $50 I ever spent (bought mine from Coralscaping). Totally non-invasive to your tank, 100% successful, and no effort on the part of the Aquarist. Great combination!!!