Neptune Branching Hammer CoralHow to Care for Neptune Hammer Coral: (written by Dave Burr) The Neptune Hammer Coral is a great beginner coral and will sway back and forth to the currents in the aquarium. Hammer Corals are a favorite of many because of the sense of motion they bring to a reef tank. Tentacles: They do have sweeper tentacles that can extend 2" 4" at night and sting nearby corals. Hammer Corals may be placed next to other Euphyllia species such as Frogspawn Coral and