Hammer Coral Green (Euphyllia ancora)

Euphyllia ancora, the Hammer Coral, is one of the most iconic and popular LPS corals in the reef hobby, extending long, hammer-tipped tentacles with vivid green to yellow-green colouration that sway gently in moderate flow. It is moderately aggressive via sweeper tentacles that can extend significantly at night, requiring adequate spacing from other corals. Aquacultured specimens are widely available and more robust than wild-collected pieces.

Medium PAR (100–200). Moderate, indirect flow — direct strong flow causes tentacle retraction and bleaching. Alk 8–10 dKH, Ca 400–450 ppm, temp 24–27°C. Keep at least 15–20 cm clear of other corals — sweeper tentacles extend 10–15 cm at night. Target feed meaty foods (mysis, reef roids) 1–2 times per week for optimal growth and polyp extension. Brown jelly disease is a risk in stressed specimens — maintain pristine water quality.