Zoanthid (Zoa) Coral Care Guide
Zoanthids, commonly called "Zoas," are popular soft corals in reef aquariums due to their vibrant colors, ease of care, and fast growth. They are ideal for beginners and experienced reef keepers alike.
1. Growth Rate
- Zoanthids are moderate to fast growers, depending on water quality, lighting, and feeding.
- Some varieties grow rapidly, covering rocks and frag plugs, while others grow slowly.
2. Lighting Requirements
- Moderate to High Light (50-150 PAR)
- They adapt well to different lighting intensities but develop the best colors under appropriate light.
- Too much light can cause color bleaching, while too little light can lead to stretching (polyps reaching for light).
- Use blue-spectrum LEDs for best fluorescence and coloration.
3. Care & Water Parameters
Zoas are hardy but require stable water conditions:
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Temperature: 76-80°F (24-27°C)
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Salinity: 1.024-1.026 (SG)
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pH: 8.1-8.4
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Alkalinity: 8-12 dKH
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Calcium: 400-450 ppm
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Magnesium: 1250-1350 ppm
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Nitrates: <10 ppm (low to moderate is okay)
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Phosphates: <0.05 ppm (keep low to prevent algae issues)
4. Placement in the Tank
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Low to Mid Placement: They can thrive in various spots but prefer moderate flow and light.
- Avoid direct high flow, which may cause polyps to close.
- Place on rocks or frag racks where they can spread easily.
5. Water Flow
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Moderate, indirect flow is ideal.
- Too much flow can cause polyps to remain closed, while too little flow may allow detritus and algae to build up.
6. Feeding & Nutrition
- Zoas have symbiotic zooxanthellae, meaning they get energy from light but benefit from supplemental feeding.
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Target or broadcast feed once a week with:
- Phytoplankton
- Reef Roids
- Coral Frenzy
- Amino acids
- Feeding enhances growth and coloration but is not necessary for survival.
7. Common Issues & Pests
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Zoanthid Pox: Small white spots; treat with Furan-2 dips.
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Nudibranchs & Spiders: Tiny predators that eat Zoas; dip in CoralRx or Lugol’s iodine.
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Algae Overgrowth: Can smother Zoas; maintain good water quality and flow.
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Closed Polyps: Could be due to poor water conditions, pests, or excessive light/flow.
8. Fragging & Propagation
- Zoas can be fragged easily by cutting between polyps and attaching them to frag plugs with reef glue.
- Handle with care as they contain Palytoxin, a harmful toxin—always wear gloves and eye protection when fragging.
Conclusion
Zoas are a beautiful and beginner-friendly coral that add vibrant colors to a reef tank. With proper lighting, stable water parameters, moderate flow, and occasional feeding, they will thrive and spread over time.
