Often overlooked, magnesium plays a critical role in chemical and biological processes in an aquarists saltwater aquarium. The magnesium content in natural saltwater is only behind that of sodium and chloride, making it a major element as opposed to a trace element. Magnesium is essential to all organisms for biological functions, and is very important to organisms that are skeleton building such as LPS and SPS corals. Many times we find hobbyists that are struggling with issues in their coral reef aquarium only to find deficiencies in magnesium. It is very difficult to maintain ideal calcium and alkalinity levels in saltwater without maintaining magnesium levels as well. Natural sea water has magnesium concentrations of 1280-1350 ppm. If the levels in an aquarium are below these levels, calcium and carbonates will tend to precipitate out causing issues, mainly with corals. Therefore, we suggest if you are not achieving intended results, you should check your magnesium levels on a regular basis and dose as needed. Magnesium may be found in saltwater mixes. Many of the reef mixes will have added higher concentrations of magnesium and other elements in the concoctions. Magnesium can also be found in the proper breakdown of materials such as aragonite in a calcium reactor set-up. However, the easiest way to dose magnesium is to use a liquid or a powdered form of a stand-alone supplement such as aquavitro ions.
