I have that same pink coral and it alwmost died once. In fact I thought it was dead and almost threw it out. But after some water adjustments it came back and is doing fine, double its original size. But what is it called? Is it a member of the xenia family?
Also, I have a biocube too. Mine is the 40g. I have been having a couple of problems with mine. First of all, I can't keep the water in the back tank (the one with the minimum/maximum window) to stay in between the two water markers. It keeps dropping below the minimum which causes the tank to fill up with bubbles, sometimes so many bubbles you cant see the fish. (Are the bubbles bad for the fish by the way?)
The second problem is that the fan has begun to get really loud and clangy. I have tapped on the lid a few times and it has quieted down, but I'm afraid I'm just going to break it if I keep hitting it. Besides, its just a few months old and it shouldn't be doing this.
sorry about highjacking your post and being so long winded, but we seem to have the same problems.