You can throw as much calcium and buffer solution at your aquarium as you want, but without the proper amount of magnesium, those frequent dosing are just useless. Magnesium dosing, in its simplest explanation, helps calcifying corals take up the reef building materials. If magnesium isn’t maintained at appropriate levels, then corals will grow slowly and you’ll be wasting all of those fancy products. Magnesium levels need to be maintained between 1200 and 130o ppm, and obviously water testing is required to dial to those numbers. Another benefit to magnesium dosing is a reduction in algae. For years, hobbyists have been touting magnesium’s ability to kill hair algae.