Elkhorn Coral Care Guide
Elkhorn Coral (Acropora palmata) is a SPS coral. Care covers 300-450 PAR, very-high flow, reef parameters and feeding; expert level.
Compiled by Aquairi from published sources · Published · Updated
Overview
Elkhorn Coral (Acropora palmata) is a SPS coral in the family Acroporidae. Caribbean Acropora with broad, antler-like flat plates. CITES II; rarely found in trade outside aquaculture.
Taxonomy
- Family: Acroporidae
- Genus: Acropora
- Scientific name: Acropora palmata
- Common synonyms: Elkhorn, Atlantic Elkhorn
Habitat
In the wild, Acropora palmata is reported from Caribbean, where it occupies shallow reef flats and upper slopes (typically 1-15 m). The species adopts a plating growth form on hard substrate within zooxanthellate reef communities.
Tank requirements
- Salinity (specific gravity): 1.025-1.026
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness (dKH): 7.5-9
- Calcium: 420-450 ppm
- Magnesium: 1300-1400 ppm
- Phosphate (max): 0.03 ppm
- Nitrate (max): 5 ppm
- Minimum system age: 1 year
Placement and lighting
- PAR (placement zone): 300-450 PAR
- Water flow: very-high
Place this SPS coral on the upper rockwork where light is bright and water movement is strong, ideally turbulent rather than laminar. Acclimate gradually to high PAR over 2-3 weeks to avoid bleaching. SPS demand a mature system: stable alkalinity, calcium, and magnesium with phosphate and nitrate kept ultra-low.
Feeding
Acropora palmata hosts symbiotic zooxanthellae and derives most of its energy through photosynthesis. Additional feeding is generally not required when lighting is adequate.
Compatibility
This coral is passive toward neighbours. Reef-safe with most fish and invertebrates.
Care notes
Difficulty level: expert. Reported skeletal growth in well-tuned reef tanks is approximately 0.5-1.5 cm/month. Propagation by fragmentation is straightforward for plating 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.
Acropora palmata Propagation Guide
Overview
Acropora palmata, the elkhorn coral, is a Caribbean reef-builder whose hard, antler-like structures form many broad, flattened branches resembling elk antlers. It is found throughout the Bahamas, Florida, the Caribbean and to the northern shores of Venezuela, in shallow water from about 1 to 5 metres deep. It thrives best in high-energy zones where wave action is frequent, since wave action increases fragmentation and allows more new colonies to form.
Reproductive Mode
Elkhorn coral reproduces primarily through fragmentation, where fragments break off during storms and form genetically identical colonies. Restoration aquaculture relies on this same asexual process to multiply the species in nurseries.
Fragging / Asexual Propagation
Restoration programmes fragment branches from donor colonies and grow the frags in offshore or land-based nurseries before outplanting them onto degraded reefs. Elkhorn grows quickly, averaging 5 to 10 cm per year and up to 13 cm of branch length a year in healthy colonies, so nursery-grown frags reach outplant size relatively fast.
- Branches are fragmented from healthy donor colonies within a restoration programme.
- Frags are mounted in ocean nurseries on structures or suspended supports, or in land tanks.
- Frags are grown out to a robust size before outplanting.
- Colonies are outplanted into shallow, high-energy reef zones where the species naturally thrives.
Conditions for Propagation
Elkhorn needs strong water movement and bright light, reflecting its natural shallow wave-zone habitat. As an Acropora it requires stable temperature, salinity, alkalinity, calcium and magnesium; warming waters drive bleaching, so stability is critical for healing frags.
Sexual Reproduction
Sexual reproduction occurs via broadcast spawning once per year, after a full moon in late summer, during July, August or September. Restoration programmes use spawning to add genetic diversity beyond fragmentation.