A two-part solution for replenishing calcium and alkalinity. Adjusts calcium, magnesium and strontium ions to Natural Seawater ratios, and achieves a balanced ionic residual. Promotes the optimal conditions for stony corals and coralline algae. Now available in a new 8 oz size (two 8 oz bottles) for use in Nano Aquariums, two 16oz. bottles, two 32oz. bottles, or as a 1 gallon concentrate.