Reef Calciumis a concentrated gluconate calcium supplement designed to promote accelerated growth of all corals in the reef aquarium. It has a pH of 8.2, is neither acidic nor caustic, and is based on a gluconate polymer demonstrated to be safe, effective, and avidly utilized by corals. It also contains a proportionate amount of gluconate strontium. It also has the side benefit of enhancing denitrification. Reef Calciummay be used alone, but, in densely populated reef aquaria, it should be used with Reef Completeor Reef Advantageto supply more calcium than can be provided by Reef Calciumalone. It is a companion product to Reef Complete(or Reef Advantage)and Reef Plus. It is fully compatible with Reef Builder, Marine Buffer,and other Seachem products. Each 100 mL treats up to 5,000 gallons.