What Is a Duncan Coral?

The Duncan coral is a large polyp stony (LPS) coral native to the Indo-Pacific. It features long, fleshy tentacles and a vibrant green or purple center. Known for its peaceful temperament and fast growth, the Duncan is a reef tank favorite.

Ideal Tank Conditions

• Lighting: Low to moderate (50–150 PAR). Duncans adapt well to a range of lighting conditions.
• Water Flow: Low to medium. Avoid direct, laminar flow to prevent tissue damage.
• Temperature: 75–80°F (24–27°C)
• Salinity: 1.024–1.026 SG
• pH: 8.1–8.4
• Alkalinity: 8–12 dKH
• Calcium: 400–450 ppm
• Magnesium: 1250–1350 ppm

Placement Tips

Place your Duncan coral on the sand bed or lower rockwork. Ensure it has room to expand and isn’t shaded by other corals. Duncans are peaceful but can extend short sweeper tentacles, so give them space to grow.

Feeding & Nutrition

While Duncans are photosynthetic, they benefit from supplemental feeding. Offer:

• Frozen mysis or brine shrimp
• Reef Roids or powdered coral foods
• Liquid amino acid supplements

Feed 2–3 times per week for faster growth and vibrant coloration.

Growth & Fragging

Duncan corals grow by budding new heads from the base. To frag, use bone cutters to separate polyps at the skeleton. Allow frags to heal in a low-flow area before returning them to the display tank.

Common Issues

• Receding Tissue: Often caused by poor water quality or excessive flow.
• Closed Polyps: May indicate stress, pests, or sudden lighting changes.
• Algae Growth: Keep nutrients balanced and flow adequate to prevent buildup.