Seachem Reef Salt is a chemically sound blend of salts designed to replicate natural reef waters. Specifically formulated for the reef environment, it provides ideal seawater concentrations of magnesium, calcium, and strontium with proper alkalinity and pH. It contains all essential major, minor, and trace components found in natural reef waters, but contains no toxic or non-essential components such as nitrate, phosphate, silicate, arsenic, cadmium, or beryllium. Reef Salt dissolves quickly and completely. Reef Salt supports and promotes enhanced calcium and alkalinity stability to maintain calcium above Natural Sea Water (NSW) levels (400 mg/L) and provides NSW levels of bromide (65 mg/L). Aquarium Use Only! Keep Away from Children!