Instant Ocean Reef Crystals Reef Salt for Reef Aquariums FORMULATED SPECIFICALLY FOR REEF AQUARIUMS: Contains essential ocean reef elements in concentrations greater than those found in natural sea water EXTRA CALCIUM: Encourages stony coral and coralline algae growth. EXTRA TRACE ELEMENTS: Provides vital nutrients. EXTRA VITAMINS: Helps promote growth and survival of corals, anemones and other invertebrates in a captive environment. DETOXIFIES METALS: Neutralizes traces of heavy metals found in tap water.