Magnesium Liquid Dupla Marin provides all invertebrates with vital magnesium. Optimises the relation of the concentrations of Ca and Mg and enhances skeleton building of corals. Supports the growth of haptophytes. Enriched with vital hydrogen carbonates. 1,000ml Magnesium Liquid contains 50,000 mg MG. The optimum Magnesium content of seawater is 1,350 mg/l.