Corals close/stress after lunch

[Tbowser]

I have some ZOAs and a LPS frag in my tank. After around noon the ZOAs close up and the LPS starts to look stressed. I thought it was maybe lighting but even bringing the lighting down over a week did not seem to solve the problem.

Not sure why my calcium is reading so high since I don't dose any and I do at least 10% water change a week. And I can't say I usually test for calcium since I don't dose it.

Temp: 77.8 - 78.5
Salinity: 34.8ppt
Nitrates: 10
p04: .03
dkh: 7.5
Ca: 600

-Tim

 

[Reefing_addiction]

How old is your tank?
Got pictures?
Maybe your alk is to low? I’ve heard 9 is a magic number

 

[Tbowser]

The tank is over 8 years old but it went through a mini-crash about 5 months back. But everything has seemed to be in check. It's weird to me that it happens after a certain time in the day but nothing changes over time except my lighting and when it is happening the intensity has already been dropping for over an hour.

The lps is the orange bit top center. The zoos are all to the right of the tank but they are all closed right now.

I think you are right about the alk and it's my bad I haven't been checking it for a while. I figure with the water changes I was doing that the alk was being added back enough.

 

[Tbowser]

Just an update. All water params are the same except DKH which is now 7.8 and I will continue to slowly raise it to 9. Nothing looks worse but at the same time, nothing looks better either.

-Tim