Alright, I'm at a loss. I have a year old zoanthid heavy mixed reef. All corals have been beautiful and healthy. Tons of growth. I feed reef roids 2x a week with some coral aminos mixed in. PH is consistent at 8.0, salinity 1.026, magnesium 1350, calcium 450, Alkalinity 10, ammonia 0, Nitrite 0, Nitrate 5, phosphate .10. My problem is with most of my zoas closing when the white lights go off, everything else is thriving. My nitrates used to be around 50 so I started carbon dosing due to bubble algae. It has worked great as my nitrates are steady at 5 now. Normally I would just say the problem is that the zoas liked the dirtier water since they started closing as the nitrates dropped, but here's what is throwing me off. They are all open and happy when the white/color spectrum is on. When the whites go off and its just the blues running, they start to close. This is like clockwork every day. I'm going to cut back on the dosing and get my Nitrates back up a bit to see what happens, but it's just weird that they only close when the whites go off. I have not adjusted the lighting at all. Has anyone else had this problem? Side note, even tho they are closed for half of the day, they are still growing and spreading. I've attached 2 photos. One where all the zoas were open and the other was from today. Any info would help, thanks.