Coral help

[Qumanchu2099]

I need help figuring out my tank. The past year I upgraded my tank from a 55g to a 180g I had no issues in the 55 everything grew fine. I was dosing afr. I never even checked parameters other than nitrates. My tank was fine and I had no issues. Then I upgraded to the 180 and that’s where the problems started. My acans started to shrink my fox coral soon followed and I wasn’t sure what was going on. I started checking parameters my calcium was really high and so was my alkalinity.
Ca. 505
dKH 11.5
Mag. 1380
This was in May 2023
Fast forward to today November 2023
My euphyllia has started to shrink and my goni’s have started to die off. So I checked my parameters and my
Ca. 505
dKH 10.9
Mag. 1050
So here i am freaking out because I don’t know how to raise it (mag) and I don’t know what is sucking it up. I have been doing weekly 25% water changes and dosing afr. And I can’t figure out how my mag is so low.

 

[kbnh]

have you checked the magnesium with another test or a sample of fresh saltwater to see if the results are correct? Maybe the test has expired?