High Magnesium.

lakai · May 29, 2020

My magnesium has always been between 1450-1500. I can't get it to come down and I've never had to dose it before. Mag levels are the same across trident, icp, and other mag test kits. It doesn't seem to be a problem but I would like to make some sense of it. Thanks advance for any help.

andrewey · May 29, 2020

What salt do you use and how frequently do you perform water changes?

Randy Holmes-Farley · May 29, 2020

Presumably it is from the salt mix. Consumption of magnesium is very slow, with a max about 1/10th of the calcium consumption.

lakai · May 29, 2020

andrewey said:
What salt do you use and how frequently do you perform water changes?

Instant ocean 10% bi monthly. I switched back to tropic Marin pro reef this last water change it’s down to 1360 now

Randy Holmes-Farley · May 30, 2020

Your salinity may be higher than you think, or the magnesium result may be test error. IO does not mix that high in magnesium at 35 ppt.

The drop you report suggests likely testing error/variability because you'd need a ton of changes to drop magnesium taht much.

At 1450 ppm, a 10% change with 1300 ppm magnesium only drops magnesium to 1435 ppm.