I think that with the age of your tank and dry rock, that it is only a matter of time. And please don't ever panic (unless water is hitting the floor).Because I've literally never had this style of coral and was asking if it's okay. It looks okay based on the photos I've looked at but that's all I have to go off of. Lol. Just because I'm asking about it doesn't mean I think it's distressed or dying. I'm not in panic mode or anything.