Zoas on top are closed and scrunched up, underneath are open and flourishing. Why?

[testuser]

I have a zoa piece that has heads underneath and on top. Underneath, they are flourishing and opened pretty wide. On top, they are all of a sudden all closed up, and one looks like it's becoming deformed. I turned the brightness of my light down from 50 to 40% today to see if it would help, but putting my macro algae over the top to help shade for a week did nothing. Besides lighting, I'm confused why the other half of the zoa is doing really well. Could it need more light instead? I wouldn't think so, but what other thoughts?

 

[Saltyreef]

Could be a number of variables.

Post parameters we can rule out water chemistry

 

[testuser]

Could be a number of variables.

Post parameters we can rule out water chemistry

Sure. I don't think that it's the water chemistry, because that would be a pretty crazy anomaly for half of the zoa to be good with it (and interesting).

Nitrates: 5
Phosphates: 0.03
Alkalinity: 9
Calcium: 420
Magnesium: 1300
pH: 8.15
Salinity: 1.025

 

[testuser]

Sure. I don't think that it's the water chemistry, because that would be a pretty crazy anomaly for half of the zoa to be good with it (and interesting).

Nitrates: 5
Phosphates: 0.03
Alkalinity: 9
Calcium: 420
Magnesium: 1300
pH: 8.15
Salinity: 1.025

Well, the zoa is looking fine now but now my micromussa is puckering up with the same water chemistry as above. I turned down the lights way low and it didn't change anything. I am starting to see its skeleton. However, at night it fully extends with tentacles out and all. I find it bizarre that only now after several months is it starting to dislike the light. Thoughts?

 

[testuser]

Well, the zoa is looking fine now but now my micromussa is puckering up with the same water chemistry as above. I turned down the lights way low and it didn't change anything. I am starting to see its skeleton. However, at night it fully extends with tentacles out and all. I find it bizarre that only now after several months is it starting to dislike the light. Thoughts?

For better context, here's a picture of it. I did just feed it, but didn't notice much of a response.