I have noticed some sort of white growth on my zoas. Not exactly sure what it is and the zoas open up just fine. I like of looks like I made a trail of super glue gel between the polyps. I got a decent picture but it is very blue from the CF-Quad lights. You can sort of see what I am talking about around the right side of the colony. I had to poke them a little so they close up so you can see it.