This is one of those corals that can multiply so quickly that it overtakes your entire tank. But, they provide a nice waving motion in the tank and are very interesting. The problem is when they attach to another rock, they leave enough behind to start a whole new stalk and before you know it they are dominating everything else in the tank. I keep mine on a rock at the very top of the formation and since they seem to always move in the "upward" direction they run out of room. Periodically, I remove that rock and thin out the Xenia. The best way to get them in another part of your tank is to put a small rock in their way and let them move to it.