Warner Marine Research Balanced-Ion Magnesium Supplement Magnesium is the third most abundant ion in saltwater, behind only Sodium and Chloride. It is essential to the calcification process, utilized along with Calcium and Carbonates to build skeletal structures or shells. It is also necessary to a great number of biochemical processes in every living marine organism. Magnesium also plays an important role in the stability of Calcium and Alkalinity. Warner Marine Research Balanced-Ion Magnesium Supplement is the premier Magnesium product available in the hobby. It is unique, in that it is formulated to add several forms of Magnesium in a balanced ratio as not to disturb the ionic balance of the marine or reef aquarium. In addition it is highly concentrated, containing over 70,000 ppm Magnesium for effective Magnesium supplementation in the marine or reef aquarium. Available in 8oz, 16oz, 32oz and one gallon sizes.