Hammer Coral (Euphyllia ancora) Lighting Requirements: Moderate to High Water Flow: Medium Care Level: Moderate Placement: Middle to Lower Levels Temperament: Aggressive The Hammer Coral is a stunning and highly sought-after species that will bring a unique touch to any reef aquarium. Named for its distinct, hammer-shaped tentacles, this coral comes in a variety of vibrant colors, from greens and yellows to deep pinks and purples. It’s an ideal choice for hobbyists who want a coral with both beauty and movement. There are two main varieties of Hammer Coral—branching and wall. The branching form features long, separate polyps that extend outward like hammers, while the wall variety creates a solid, encrusting base with the same hammer-shaped tentacles rising from it. Both forms are visually striking and provide different aesthetic options for your tank, depending on the layout and design. Hammer Corals thrive under low to moderate lighting, with a spectrum that includes both blue and white light for optimal color and health. They prefer medium water flow, which helps keep their tentacles extended and full. Although they will do well with the natural nutrients provided by the symbiotic zooxanthellae, regular feeding of small plankton or coral foods can promote robust growth and vibrant coloration. One thing to keep in mind is that Hammer Corals are known for their aggressive nature. Their stinging tentacles can damage or harm neighboring corals, so be sure to give them space to avoid any coral warfare. Tip: If you're looking for variety, the branching form is great for creating dynamic, 3D displays, while the wall form is perfect for filling out spaces or creating a dense structure.