How much light and flow does Hammer coral need?

Stony coral · LPS, medium light at roughly 100–150 µmol·m⁻²·s⁻¹ PAR, with medium flow. Light and flow must match: high light with weak flow burns tips, strong flow with weak light thins the tissue.

Will Hammer coral attack neighbouring corals?

It has sweeper tentacles: at night it extends tentacles several times its own width and burns whatever they reach. Leave at least one adult diameter between it and its neighbours.

Does Hammer coral need feeding?

Optional. It survives without feeding, but regular small doses improve growth and colour.

What water parameters does Hammer coral need?

24–26 °C, specific gravity 1.024–1.026, 7–9 dKH, 400–450 mg/L calcium, 1250–1350 mg/L magnesium. That is only 2 dKH wide, so stability matters more than hitting a particular number.

Is Hammer coral a good beginner coral?

Difficulty: beginner. Growth: medium. Place it in the midground. Spacing: 15 cm or more. Sweepers only come out at night, so peaceful daytime looks prove nothing.

G-03 / 08Marine

Hammer coral锤头珊瑚（榔头）

Fimbriaphyllia ancora · Euphylliidae

Anchor coral: tentacle tips shaped like anchors or hammers, and the toughest of the three hammer-type LPS for a beginner.

Illustration to come

G-03 / 08 · Hammer coral Fimbriaphyllia ancora

SpecificationsCoral atlas

Name: 锤头珊瑚（榔头）
Scientific name: Fimbriaphyllia ancora
Family: Euphylliidae
Origin: Reefs of the Indo-Pacific, from the Red Sea to the Great Barrier Reef
Type: Stony coral · LPS
Light: Medium light
PAR: 100–150
Flow: Medium flow
Aggression: Sweeper tentacles
Feeding: Optional feeding
Alkalinity: 7–9 dKH
Calcium: 400–450 mg/L
Magnesium: 1250–1350 mg/L
Salinity: 1.024–1.026 SG
Growth: Medium
Placement: Midground
Level: Beginner

Water requirementsMarine

Temp.24–26 °C

pH8.1–8.4

Salinity1.024–1.026 SG

Alkalinity7–9 dKH

Units: temperature in °C, hardness in German degrees (dGH / dKH), marine salinity as specific gravity at 25 °C, volume in litres. These are the values recorded for the species and do not follow the site unit switcher.

Keeping notes

1Spacing: 15 cm or more. Sweepers only come out at night, so peaceful daytime looks prove nothing.
2Flow: medium; keep it out of a direct outlet stream, which wears the cup rim down over time.
3Feeding: optional; one feed a week visibly speeds up splitting.
4Water tolerance: fairly tolerant of mild swings; steady calcium and alkalinity are what keep the anchor-shaped skeleton forming neatly.
5Growth form: cups keep splitting into dense hammer clusters, making it the safest stepping stone between soft and stony corals.

Frequently asked questions

How much light and flow does Hammer coral need?: Stony coral · LPS, medium light at roughly 100–150 µmol·m⁻²·s⁻¹ PAR, with medium flow. Light and flow must match: high light with weak flow burns tips, strong flow with weak light thins the tissue.
Will Hammer coral attack neighbouring corals?: It has sweeper tentacles: at night it extends tentacles several times its own width and burns whatever they reach. Leave at least one adult diameter between it and its neighbours.
Does Hammer coral need feeding?: Optional. It survives without feeding, but regular small doses improve growth and colour.
What water parameters does Hammer coral need?: 24–26 °C, specific gravity 1.024–1.026, 7–9 dKH, 400–450 mg/L calcium, 1250–1350 mg/L magnesium. That is only 2 dKH wide, so stability matters more than hitting a particular number.
Is Hammer coral a good beginner coral?: Difficulty: beginner. Growth: medium. Place it in the midground. Spacing: 15 cm or more. Sweepers only come out at night, so peaceful daytime looks prove nothing.