Open Brain Coral Care Guide
Open Brain Coral (Trachyphyllia geoffroyi) is a LPS coral. Care covers 50-150 PAR, low flow, reef parameters and feeding; intermediate level.
Overview
Open Brain Coral (Trachyphyllia geoffroyi) is a LPS coral in the family Merulinidae. Free-living LPS that sits on sandbed; inflates a fleshy mantle by day. Wide color range from green to red and rainbow.
Taxonomy
- Family: Merulinidae
- Genus: Trachyphyllia
- Scientific name: Trachyphyllia geoffroyi
- Common synonyms: Trachy, Folded Brain
Habitat
In the wild, Trachyphyllia geoffroyi is reported from Indo-Pacific, Australia, where it occupies mid to lower reef slopes and lagoons (typically 5-30 m). The species adopts a massive growth form on hard substrate within zooxanthellate reef communities.
Tank requirements
- Salinity (specific gravity): 1.024-1.026
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness (dKH): 8-11
- Calcium: 400-450 ppm
- Magnesium: 1280-1350 ppm
- Phosphate (max): 0.03 ppm
- Nitrate (max): 5 ppm
- Minimum system age: 6 months
Placement and lighting
- PAR (placement zone): 50-150 PAR
- Water flow: low
Mount this LPS coral on the lower or mid rockwork or on the sand bed (for free-living forms) where light is moderate. Strong direct flow can damage the fleshy tissue; aim for indirect, varied movement.
Feeding
Trachyphyllia geoffroyi hosts symbiotic zooxanthellae and derives most of its energy through photosynthesis. Supplemental target feeding accelerates growth and supports colouration; commonly accepted items include mysis, brine, reef-roids, amino-acids. Feed once or twice per week after lights-out, when polyps are extended.
Compatibility
This coral is moderately aggressive toward neighbours. It extends sweeper tentacles capable of stinging adjacent corals, so leave generous spacing (10-20 cm) between colonies. Reef-safe with most fish and invertebrates.
Care notes
Difficulty level: intermediate. Reported skeletal growth in well-tuned reef tanks is approximately 0.1-0.3 cm/month. Propagation by fragmentation is straightforward for massive colonies — separate branches or polyps with a bone cutter, glue to plug, allow 1-2 weeks for healing. Maintain stable alkalinity (avoid swings above ±0.5 dKH per day) to preserve tissue health.