Solution of Hydrated Magnesium Salts for Use in Reef and Marine Aquaria Overview Safely increases magnesium concentration in all marine and reef aquaria. Utilizes specific magnesium salts to obtain the desired results. May be used to attain and maintain a magnesium concentration in excess of 1,500 ppm as desired by aquarist. Maintaining an elevated magnesium concentration, relative to the average natural seawater concentration, for a prolonged period of time may be of benefit to reef aquaria in certain situations, and should be attempted by experienced aquarists only. 75,000 ppm magnesium