The zoa colony on the right has been slowly decreasing in numbers since January, when I moved my tank. Before, this particular colony went from just a few polyps to 80+ in just six months. Now, as my other zoas continue to grow, this colony just gets smaller. I did notice asterinias in my tank a couple months back and tried to banish the ones I could to the sump...I know there are still some in the dt, I just never see them. I would think if it were asterinas eating my zoas, it wouldn't just be one particular colony! Then again, maybe they're super-delicious. Any other ideas what the problem could be, besides asterinas?