CaMg+ is a component of the unique organic BioThrive Grow and BioThrive Bloom formula. CaMg+ is derived from an all natural source instead of calcium nitrate. It must be added to make calcium available to plants grown hydroponically. Calcium is an essential element that plants use to build strong healthy cell linings. It also promotes resistence to disease. In general, it is a great supplement containing additional minerals necessary for plant structure.