Magnesium magically stable (and high)

[Reef Pilot]

I was running about 1500+ mg in my tank for a while, too. I never dose mg, but I dose Seachem Reef Advantage Calcium which adds mg along with the ca. I was also using Royal Nature salt for a time which I think had more mg in it. Lately I have been using just the cheap Instant Ocean salt, and my mg is now running around a more normal 1200.