Overview Kent Marine Sea Salt has been designed to provide all of the necessary minerals present in the ocean, down to the minute trace minerals. Superior dissolvability. Nitrate-free and phosphate-free, it contains an enhanced blend of important nutrients, both vitamins and minerals. Your marine tank or reef with everything the animals and algae need not only to survive, but thrive in their artificial environment. Because of cost, many of these minerals are left out of conventional synthetic salt mixtures, depriving the animals of necessary nutrients, and may suffer. For fish only and reef aquariums.