Zoas not staying open

[Mark687]

I have a reef breeders photon 24 on my 60 cube I have turn the intensity way down and still my zoas will not stay open the whole day. They are open happy in the morning but throughout the day they start closing up after the whites come on. Can you please help me I'm not really sure what I'm doing wrong. I do have snails and hermit crabs yellow tang to clown fish purple fire fishyellow watchmen goby.

 

[organism]

Have you tried turning the whites off entirely to see if they still close up? Could be a lot of factors like pests, salinity, alkalinity... Are they getting decent water movement?