A concentrated (80000 ppm) optimized blend of magnesium chloride and sulfate salts designed to restore depleted levels of magnesium with minimal impact to the ionic ratios found in natural sea water. Reef Advantage Magnesium™ contains no ammonia! This is a common contaminant in every liquid magnesium supplement on the market. Severely depleted levels of magnesium (below 800 mg/L) can cause depressed pH levels and an inability to maintain proper calcium levels. Magnesium depletion is commonly associated with the use of kalkwasser. 600 g treats 10000 L (2500 gallons).