My Favia is starting to develop areas of tissue loss with some polyp recession around the base. My tank parameters are well within acceptable limits (alk-8.3) and all other LPS corals are doing well. The time period of this process rules out RTN. It could be STN but my alk has been stable. I do try to feed it regularly with oyster eggs, rotifers, and pods, but I never see any feeding tentacles or much of a response to being fed. Any suggestions?