RAW Calcium/Mag contains 15% calcium and 3% magnesium. RAW Calcium/Mag has optimized the ratio of each element in a Water soluble formulation of calcium nitrate and magnesium sulfate so that it doesn’t leave the media salty. This product is a stand alone Calcium / Mag supplement. Do to its low dilution rates a little RAW Calcium / Mag goes a long ways. Its also ideal for preventing deficiencies, treating deficiencies and for creating optimal recipe solutions. Works in conjunction with all nutrient and feeding programs.