DiCalcium Phosphate:(CaHpo4/CaH4(PO4)2) Most homemade fish foods lack a very important component - calcium. It's essential for proper growth, and fin structure, among other vital processes. This feed additive takes care of that deficiency. It also adds phosphorus to the diet which works in combination with the calcium. Add it at approximately 2% by weight to your formula. For example, 10 lbs of paste food would take 3-4 oz of this additive. If feeding snails, you may want to go to 4% for the best shell growth. Phosphorus - 18.5 % min; Calcium - 20% min, 24% max.; Fluorine - 1850 ppm max.