Magnesium levels Dropping

Piranhapat · Feb 17, 2016

Can GFO be causing my Magnesium levels to drop. I never had to add and was always right on mark. I add BRS two parts by doser. Haven't change salt. Only thing I can think about is GFO. Plus 10% to 15% WC every week. Any ideals or its normal. Sps tank with 10 fish in 90 gal. About 120g total water.

Randy Holmes-Farley · Feb 17, 2016

No, I do not believe GFO impacts magnesium except that GFO and reducing phosphate may possibly increase the deposition of calcium carbonate (both biological and abiotic), and along with that increased demand for calcium and alkalinity will come some increase in demand for magnesium which gets into calcium carbonate in place of some of the calcium.