Green Duncan CoralHow to Care for Green Duncan Coral: (written by Dave Burr) Green Duncan Corals are easy to keep and grow well in most reef aquariums. They are a great choice for adding a splash of color to lower flow, lower light areas of your reef aquarium. Placement: Mount the Duncan Coral using IC gel glue, or putty, on an exposed rock or ledge in the lower two thirds of the aquarium where they will receive low to moderate currents and low to moderate lighting.