Zoas opening in morning, closing about noon. Help please

[BHReefer]

Hi all-

I have a few zoa colonies that seem to want to close half way thru the day. I have others that are open all day. I do not have par info but have moved the angry colonies to lower light areas, that has not seemed to help. I have blues on earlier in the day and whites start later (zoas seems to close up before whites come on). Lighting duration 11 hours full, one hour ramp up/down. Also my pH is a bit high and I recall reading that may cause issues. Photos are the same zoa rock, first pic about 10am aquarium time and second about 4 pm. Help pls, TY

Parameters
pH 8.4
PO4 0.1ppm
NO3 3ppm
dKH 8.5
Ca 420ppm
Mg 1350ppm
Salinity 1.026

Thanks
CC

 

[shakacuz]

could honestly be a swing in something. or, they’re just weird like that

 

[SchrutesReefs]

My guess would be that your light schedule may be too intense. What lights and schedule are you running? If you have a 1hr ramp up and the lights come on at 10am. Then by noon you’re at full intensity, and they close up.

 

[vetteguy53081]

Sounds like the morning intensity is what it favors and the ramp up during day too bright.