Description FREE Shipping on orders over $35. *in the lower 48 states* Magnesium is a high purity form of Mg CI without ammonia, bromide and other undesirable contaminants. Magnesium should be maintained at 1300 ppm. In marine fish and 1350 ppm. In reef aquariums at a specific gravity of 1.026 .35ppt at 77F/ 25C
