After re-aquascaping my tank on Saturday. I was sitting back enjoying the fruits of my labor when I said, "wait what's that!" I found a few aiptasia on the LR that was probably hidden in my old rock arrangement. So my new mission in life is to get them out. I'm not going to pull the rock out again. A few are tucked in a "cave" section of the rockwork that will make them almost impossible to to reach with a syringe for kalk paste or Joe's Joice. After some search on the web, I found this nudibranch that eats aiptasia called a berghia. They're not cheap. Has anyone ever heard or used these?