Hey!
got tagged on here! haha
If the zoas are closing up, here are a few things you can check for:
1. Are there any copepods in your tank that are consistently annoying the zoa/paly (I usually check when the lights go out)
2. Do you see any nuisance algae growing on the closed polyps? If so, use a turkey baster to blow them off. The algae can prevent the polyp from opening again.
3. Do you have hermit crabs? If so, check them at night to see if their picking around the zoas. That could piss them off and they could stay closed.
4. I notice in your picture that the zoas in the back are also closed. Is this the same reason? same coral?
5. Do a quick freshwater dip on the zoas. dip it and swish it around to see if any critters fall off. (could be a sign of bad bugs in your system)
Remedies:
Use a turkey baster to blow at the polyps every day to take off any algae that can grow on them
Freshwater dip, coralrx, coral revive. Any of these are good
Move the corals to lower light for now (2-3 days to see how they react)
keep an eye out for critters bugging the polyps!
Let me know how this goes!!