The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
use a small insulin needle available at the drug store. fill with kalkwasser, mixed as you would to dose it. put needle under water, carefully insert needle into aiptasia's "flesh" and inject as small a squirt as possible into it. it will shrivle and perish almost immediately.
It worked for me awhile back but I needed a couple of treatments to get the stubborn ones. The guy at the pharmacy looked at me kinda funny when I told him I needed a needle for my reef tank.