Specially formulated mixture of dissolved solids (also called general hardness or GH) which includes major salts of sodium, magnesium, calcium, and potassium together with all necessary minor and trace minerals. Provides natural water chemistry for the conversion of reverse osmosis, distilled or deionized water for fresh water fish and plants. Provides a balanced electrolyte system. Useful for all fresh water fish, including Discus. Contains no phosphates, nitrates or organics to pollute the system!