Coral Care Info Hammer

Hammer Coral (Euphyllia ancora and Euphyllia parancora) is one of the most recognizable and popular large polyp stony corals in the reef aquarium hobby. Known for its hammer- or anchor-shaped tentacle tips and flowing movement, it adds both structure and motion to reef tanks. Hammer corals are commonly used as centerpiece corals and are well suited for both mixed reefs and LPS-dominant systems when given proper care and space.

Care Requirements

Lighting (PAR Range)

• Hammer corals do best in 80-150 PAR.
• Moderate lighting supports strong coloration and healthy extension.
• Too much light can cause bleaching or tissue stress.
• Always acclimate new specimens slowly, especially those from new arrival corals.

Flow

• Moderate, indirect flow is ideal.
• Flow should create a gentle swaying motion of the tentacles.
• Direct, strong flow can damage tissue and prevent full extension.
• Low flow may allow debris to settle on the coral.

Placement

• Best placed in the middle to lower areas of the aquarium.
• Provide enough space for full extension and movement.
• Keep distance from other corals due to sweeper tentacles.
• Placement is important in tanks with small polyp stonies corals, which can be damaged by contact.

Aggression

• Moderately aggressive coral.
• Can extend sweeper tentacles that sting nearby corals.
• Generally less aggressive than Torch corals but still requires spacing.
• Should not be placed too close to other LPS or SPS corals.

Growth Rate

• Moderate growth under stable conditions.
• Branching varieties can grow faster than wall types.
• Can develop into large multi-head colonies over time.
• Stable alkalinity and calcium levels support growth.

Feeding

Hammer corals benefit from supplemental feeding, although they receive most of their energy from photosynthesis. Feeding can improve growth, coloration, and overall health. Newly introduced specimens from newest corals should be allowed to settle before regular feeding begins.

• Feed meaty foods such as mysis shrimp, brine shrimp, or coral-specific foods.
• Feed once or twice per week for best results.
• Avoid overfeeding to maintain stable water quality.

Tank Compatibility

Hammer corals are commonly kept in mixed reef aquariums but require careful placement due to their ability to sting nearby corals. They may coexist with other Euphyllia in some cases, but spacing is still important. In tanks that include soft corals or spreading species like zoanthids, providing enough space helps prevent contact and damage.

• Avoid placing near delicate or non-aggressive corals.
• Allow room for sweeper tentacles and expansion.
• Compatible with most reef-safe fish and invertebrates.

Common Problems

• Tissue recession caused by unstable parameters or excessive flow.
• Brown jelly disease, which can spread quickly if untreated.
• Bleaching from excessive light exposure.
• Damage from nearby aggressive corals.

Tips for Success

• Maintain stable alkalinity, calcium, and magnesium levels.
• Provide moderate flow that allows gentle movement.
• Acclimate slowly to lighting changes.
• Give enough space to prevent aggression issues.
• Monitor polyp extension regularly as a health indicator.

Frequently Asked Questions

Is Hammer coral aggressive?
Hammer corals are moderately aggressive and can extend sweeper tentacles that sting nearby corals, so proper spacing is important.

Can Hammer coral live with other Euphyllia?
In some cases, Hammer corals can coexist with other Euphyllia species, but they should still be given space to prevent damage.

How fast does Hammer coral grow?
Hammer corals have a moderate growth rate, with branching types typically growing faster than wall varieties.

Do Hammer corals need feeding?
They can survive on light alone, but supplemental feeding can improve growth and overall health.

Hammer corals are a top choice for reef keepers looking to add movement, structure, and bold color to their aquarium. With proper care, they can grow into impressive colonies and become a centerpiece in the tank. You can explore similar species in our large polyp stonies corals collection, browse larger pieces in our new arrival coral colonies, discover standout pieces in our featured corals, learn about our systems on our facility page, and stay updated through the Extreme Corals news and updates blog.