Magnesium issue

[Myka]

Originally Posted by patpare

Yes I did at 12.5% (5gallon) 4hrs befor I tested my water.
I have been adding up to 1 1/4cups of seachem advance mag per week for the past month.
I should mention that my tank is sps dominant.

What's the volume of your tank? Which salt are you using?

For example; IO is around 1100 ppm, so every time you do a water change you're going backwards unless you add Mg to the freshly mixed saltwater.