Magnesium – an agent to maintain constant levels of magnesium in coral reef aquaria. Dissolve 10g of the product and 50g of Calcium Aquaforest in 1000ml of deionized water. To maintain ion equilibrium, use KH Buffer and Reef Mineral Salt Aquaforest products as well. 10g Magnesium in 100l of water increases by about 12mg /l (ppm ) levels of magnesium. The recommended magnesium level in coral reef aquaria is 1280-1350 mg/L. Contains MgCl2.