Zoas closing when white lights go off

[JayStro81]

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.

 

[Tinvn]

I think It is normal , because zoas are used to strong light , so when you turn off white light , some will close or still open little depend on where they are in tank .

 

[JayStro81]

I think It is normal , because zoas are used to strong light , so when you turn off white light , some will close or still open little depend on where they are in tank .

What's wierd is, they were fine for months. When the white lights went off they were still open and happy. They started closing out of nowhere

 

[Tinvn]

Yes, sometime it is a message for us to know a little change in water chemistry or nutrition.

 

[pochaxoo]

Or that they really like the white light and are transitioning to a nighttime closed phase when it goes all blue? Is the spectrum gradually ramped down? If they are growing and happy for much of the daytime you might be fixing a non-problem?

 

[JayStro81]

Or that they really like the white light and are transitioning to a nighttime closed phase when it goes all blue? Is the spectrum gradually ramped down? If they are growing and happy for much of the daytime you might be fixing a non-problem?

The light spectrum has been exactly the same for a year, no changes. I did try ramping it up recently to see if it helps. I'm not too worried since the polyps look healthy and they are growing. It just stinks because I'm losing a lot of color in the tank when they are closed.

 

[LittleFidel]

They are resting.... some animals like to sleep... myself included

 

[JosephM]

I think it depends on zoas as well. My Rastas completely close soon after Lights out, watermelons partly close, and AOI stay open. They’re all quite close to each other so that rules out any differences in light, flow, blah blah blah. Corals are animals, you’re gonna get variations and they can change

 

[JayStro81]

They are resting.... some animals like to sleep... myself included

Believe me, I love my sleep. The problem was nutrients. I started adding sps to my tank so I started carbon dosing and got my nitrates down to about 5. I slowly let them creep up to about 15/20 and they are happier and open even when the white lights kick off. Sps are still doing well too