And if so what do I do about this? It looks like I have three of these guys. I read that pulling the rock up and blow torching it is a good solution. I think that I can do this will little trouble. Is this why the zoas aren't doing awesome that are near one of them?
The one with the zoas on the left hand side of the colony (below where you see the dark shadowy area from the rock above):
Below the big frag, to the left of the little one....
At the base of a rock:
Thanks for all the suggestions etc in advance....