Zoas inverting

[NemHost]

Does anyone know why zoas invert? Is it due to lighting, nutrients or pests? I’ve read differing and contradictory opinions on the matter.

 

[FredsNJReef]

wow... haven't seen that yet. Mine close up often, and they say it's because I have super low nitrates. Not sure about your issue. Is their enough flow on them? Or too much?

 

[Cary]

Mine do that after they have eaten, closed and opened again.

 

[NemHost]

Parameters are all wnl and stable
Calcium 420
Dkh 8.3
Magnesium 1380
Nitrate 5
Phosphate 0.02
Temp 77-78
Ph 8.2
Flow is low to moderate
I’ve seen it happen before and usually it’s a sign of impending doom for the affected polyp. I split this colony before for that reason. Here are some pics of some of the other blue hornets which were right next to this one but they are completely fine

 

[NemHost]

 

[JonCollegeReefer]

My newer polyps of Sunny D's do that too, not sure if it's related to their age or because they're getting less light. They seem fine though? Now I'm wondering too haha, because some have the same umbrella shape as yours.

 

[NemHost]

My newer polyps of Sunny D's do that too, not sure if it's related to their age or because they're getting less light. They seem fine though? Now I'm wondering too haha, because some have the same umbrella shape as yours.

Yes, yours are definitely fine and I’ve seen what you have in many different colonies in different tanks. What I posted about is a more extreme version and where the entire colony seems to be affected.