Secure base for freshly cut corals and polyps Contain calcium and magnesium sources for rapid growth. Unique shape aids overgrowth of encrusting coral or polyps. Ideal for use with Seachem Reef Glue. Seachem's Coral Plugs are a chemically advanced means of supplying a unique platform for the stable mounting and/or grow out of all coral fragments and colonies. They are enhanced with calcium and magnesium to aid corals in rapid and secure growth. They are designed for mounting SPS and LPS coral but are just as well suited for soft corals, colonial polyps, and various other sessile invertebrates. Coral Plugs are also designed to mesh together tightly when used in most coral culture systems so that various encrusting and colonial corals, such as zoanthids can spread quickly from plug to plug.