Duncans (Duncanopsammia axifuga) are hardy, colorful LPS corals that make an excellent choice for reef keepers wanting movement without the high demands of SPS. With the right placement and care, they grow quickly and form impressive colonies.

Placement, Flow, and Lighting

Getting placement right is the fastest way to see your Duncans thrive.

• Light: Moderate PAR (70–150). Too much light can cause retraction and pale tissue; too little slows growth.
• Flow: Low to moderate, indirect flow. Tentacles should sway gently, not whip around.
• Position: Mid to lower rockwork or on a small “island” rock so you can move them if needed.
• Space: Give at least 2–3 inches from other corals. Duncans are generally peaceful but can be irritated by aggressive neighbors.

Feeding and Day-to-Day Care

Duncans can live on light and nutrients alone, but targeted feeding noticeably boosts growth.

• Foods they love: Mysis shrimp, finely chopped seafood, high-quality LPS pellets.
• How often: 1–3 times per week is usually enough for faster head production.
• Technique: Gently baste food over the polyps with a turkey baster or pipette; turn down flow for 5–10 minutes.

Water Parameters and Troubleshooting

Stable, LPS-friendly parameters are key:

• Alkalinity: 8–9.5 dKH
• Calcium: 420–450 ppm
• Magnesium: 1300–1400 ppm
• Nitrate: 5–20 ppm; Phosphate: 0.03–0.1 ppm

Quick check: If your Duncans stay tightly closed for more than a day, check for recent changes in light, flow, or parameters before moving the coral.

Give them stable water, moderate light, gentle flow, and regular feedings, and Duncans will reward you with fast growth, full polyps, and constant motion in your reef.