H2Ocean is a new pro formula aquarium salt - produced by a solar evaporative process which produces a totally natural base salt where all of the main and trace elements are in complete balance as nature intended. The pure natural salt is then specially enhanced for aquarium use by elevating specific elements that over time become depleted, such as calcium and magnesium which are used by corals and coralline algae for growth. The formulation for H2Ocean+ salt has been developed by D-D following many months of testing and evaluation. The salt is designed to dissolve quickly and easily and to have a specific chemistry which in our opinion is the optimum formulation to maintain a healthy reef and allow regular water changes whilst maintaining a natural balance. Calcium and Magnesium levels are boosted to replace that used up through coral growth within the aquarium whereas chloride levels are slightly lowered to allow post additions of calcium and magnesium chloride with a minimized affect on the chloride balance

(information taken directly from the manufacture's website)