I have a sun coral that was doing great until I went on vacation. My husband was home taking care of it all (see post about nitrates). He was spot feeding it but now one of the heads is black. He said he still saw the yellow "fingers" come out of it. I have been home only a couple hours and haven't seen them come out. The rest of the heads seem very happy and ok! Is that head dead and do I need to worry about the rest of the heads?