Chemistry Question

Hello all! I wanted to ask a few of you chemistry buffs a question about Mag levels. I know this topic has been beaten to death in the past but I havent found any information on my specific question.

I recently had a Sunset Monti develop RTN and nearly completely disappeared within a day. The Coral was in my tank for over a year with no issues. I have 2 hammer Corals mixed in with a heavily stocked SPS tank. 1 died within 2 weeks of severe recessed polyps. The other is well on its way. I am guilty of failing to test my parameters regularly but do weekly maintenance.

Test of my parameters

PH 8.0

CAL 440

ALK 12 DKH

Mag <200 PPM..... Is this possible while maintaining high concentrations of the two previous?
My first thought was to test again. I did….twice. Same results. I began immediate dosing of Mag along with a water change.
How can Mag levels get this low without effecting both CAL and ALK? How could Mag levels drop this low with a regular maintenance and weekly water changes? It seems to me at least that this should not be possible. Any info is appreciated. Thanks!

 

What test kit are you using? Does it have an expiration date? A quick way to test would be to mix up some new SW and test that after it has mixed for a few hours. I would do this before you continue dosing just to confirm. If you do need to dose, increase no more than 100PPM per day.

 

I have referrenced it and the kit appears to be correct. Seachem Mag test kit. It is not out of date. Could I associate the loss of Hammer coral with low Mag?