Fungia and Scoly Receding Help!

[Yeet.Reefing]

I've had the scoly and fungia for about 6 months and recently it started to recede. The plate coral receded earlier made a comeback but started to die off again. I think it's due to high flow and direct lighting? I move the scoly into a shaded area but I know the flow in that spot is high but nothing crazy. I included the tank parameters below, I've been trying to dial in my dosing with all for reef and kalkwasser over the past two months with testing of course, and things seem to be stable even though Ca is low and Mg is high.

Parameters:
Alk 9.3
Ca 350
Mg 1550
NO3 25
PO4 0.03

 

[Dkmoo]

Have you tracked PH? Now vs before you started tweaking params

Kalk can change ph a lot.

 

[Yeet.Reefing]

pH has been 7.8-8.2, fluctuates but within this range

 

[Dkmoo]

If that accurate thats a really wide swing. Corals struggle when pH swings this much. Is it a 2 month ago vs now change or is that a daily swing range

I would stabilize that first. Some daily swing is expected as the co2 concentration change between day and night. Ways to mitigate this is running the refugium in the opposite light cycle, and dosing the daily kalk doses in multiple doses thru out the off light period only

I'd shoot for a daily swing of .1 to .2 and keep it in the same range every day.