AlK, calc & mg question.

[TwelveL16]

Recently my tank has been going through Alk like crazy I’ve been keeping it right around 7 by dosing baking soda here and there. I’ve been on vacation so it’s been somewhat neglected. While it was at 7 calc was 520ish with out dosing anything and mg was 1430ish with out dosing anything. I’ve recently brought Alk up gradually to 9 and I’m now maintaining it by dosing soda ash through out the day. I’ve noticed since doing so,

calc has dropped to 450 and mg has gone to 1480 with out dosing anything for mg.

Why is this? How is my MG rising?

Testing is via trident no recent reagent change.

 

[Randy Holmes-Farley Verified Community Expert]

The magnesium is either test error or a salinity change. I recommend dosing it when you dose calcium based on the calcium dose, not on testing.

https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/