I have a tan colored colt coral that I have had for about 6 months. It has been doing well. But now it isn't looking as good. I have a xenia next to it that is growing really good. I was wandering if the xenia might be causing the colt to not open as good as usual. Does anyone know? Also the colt coral has a dark brown place on one of its flowering parts and it is just hanging. Should I remove the part that looks like it is dying and if so how should I do this? If that part is dead will it kill the whole thing if left to spread? What causes the colt to turn brown and look dead on part of it?