Hammer Coral (Euphyllia Ancora): Ultimate Care Guide


Euphyllia Ancora, commonly known as Hammer Coral, is a large polyp stony (LPS) coral found in the tropical waters of the Indo-Pacific Ocean. It is found, more specifically, among the islands of Fiji, Tonga, and Solomon, as well as in the Great Barrier Reef in Australia.

Hammer Coral, also called Anchor Coral, gets its common names from the hammer or anchor shape of the tentacle polyps. This coral can be found in two different skeletal formations, branching (Euphyllia Paraancora) and wall (Euphyllia Ancora). Hammer Coral can be found in a variety of colors including purple, green, blue, gold, brown, yellow, and pink. This species is also known to be fluorescent when exposed to actinic lighting. This beautiful fluorescent coloring, as well as the hypnotic swaying of its tentacles through the water are the main draws in owning and caring for this magnificent coral.

Hammer Coral Care

Hammer Coral require stable water conditions and is considered challenging to care for. Though most aquarists agree that the beauty of this coral is worth the care required, it is not recommended for a beginner.

Hammer Coral Placement

The placement of your Hammer Coral is important for the overall health during its life in your aquarium. Hammer Corals will do well placed at the bottom of the tank, however the best placement for your Hammer Coral will depend on the specific set up your tank. It is important to place coral where they will receive adequate lighting and water flow. You can mount the coral onto a rock or ledge within the tank. Due to the aggressive nature of Hammer Coral, it is also important to keep them at least 6-8 inches from other corals and other reachable tank mates. Hammer Corals extend their tentacles in a sweeping motion and these tentacles may cause damage to other animals. Hammer Corals will pair well with other species in the Euphyllia genus.

Hammer Coral (Euphyllia Ancora)
Hammer Coral (Euphyllia Ancora)

Hammer Coral Flow Requirements

Hammer Coral receive nutrients from the water; therefore, they require indirect but moderate water flow. Hammer Corals should be swaying with the water but should not be under strain, moving uncontrollably, or be stuck flowing in one direction. The water flow will allow these corals to move beautifully through the water and provide a stunning visual element within the tank.

Hammer Coral Lighting Requirements

Hammer Coral are photosynthetic and need light to survive. However, they do not require as much light as other corals. They should be given moderate lighting in their tank and can be kept under normal output fluorescent lights. It is recommended to keep the lighting between 50-150 PAR and using a PAR meter to check levels regularly will allow you to maintain appropriate lighting. You should monitor the coral and how it responds to the lighting provided, as watching for changes in color and behavior can give you an idea of whether adjustments are necessary. Different types of hammer corals may require slightly higher or lower levels of lighting depending on the typical depth at which they are found in the wild.

Hammer Coral Supplementation and Diet

The Hammer Coral obtain many of their nutrients from the water and light around them. Keeping this species in alkaline waters with consistent levels of calcium, between 400 and 450 ppm, as well as magnesium is crucial for these corals to properly form their skeletons. Providing live feed to the coral, like meaty fish, micro-plankton, or Mysis shrimp, is recommended but not necessary. If you do provide live feed to your corals, it is best to feed only 2-3 times a week and to space the feedings out. It is also beneficial to monitor the levels of nitrate and phosphate in the water, as rising levels of these can show a decline in water quality and may affect your corals health.

Hammer Coral Temperature

Keeping appropriate temperature for the Hammer Coral is a stringent requirement for these species. Their waters must be kept at 75°F to 82°F. Water that is too hot or too cold may cause damage to the coral and result in bleaching.

Hammer Coral Water pH

Hammer Coral will suffer in waters that are too acidic. They should be kept in water with a pH level of 8.1-8.3.

Hammer Coral Growth Rate and Height

Hammer Coral growth rate is affected greatly by the conditions they live in and the care they receive. Maintaining water temperature, water flow, and sufficient lighting is important to keep this species healthy and growing. Providing enough calcium and other trace elements is crucial for their growth as well; without them the corals cannot build their skeleton, and their growth will be hindered. If proper water parameters and care is maintained, these corals can grow quickly. In the wild, the Hammer Corals size ranges from 8 inches to over 3 feet.

How to Split Hammer Coral

A Hammer Coral will split when there is a whole new skeleton formation that has grown from the original. These corals will split at the mouth and a new head will continue growing in a separate direction, with the skeleton base branching like a tree. You can split the coral by cutting or breaking off the coral fragments and placing them on a live rock or frag plug to adhere to and continue growing. Fragging is not painful for the corals, although it is important to ensure you are not cutting into live tissue on the coral, which can expose the animal to disease.

Are Hammer Coral Aggressive?

Hammer Coral are a very aggressive species of coral and should be kept where they cannot easily reach other corals or animals in the tank. It is recommended to pair them with other Euphyllias, such as Frogspawn and Torch, as opposed to corals from another family. It is also advised to keep them with fish that are not aggressive towards coral. Hammer Coral also have tentacles that can reach out 4-6 inches, so it is ideal to keep them in a large and deep tank.

Hammer Coral Dying

If you notice your Hammer Coral is not opening it is likely due to a water flow that is too direct or strong for the coral. Changing their placement within the tank or reducing the water flow may help with this. If the water flow is not found to be an issue, check the lighting to make sure it is not too bright, as that may be what is keeping them from opening. A newly added coral may take time acclimating to the tank, but if it does not open after about 3 days you should try these adjustments.

Tissue recession and exposed skeleton in Hammer Coral is caused by a lack of sufficient calcium supplementation, injury from other corals or fish, or because of infection. Check your coral for injury or infection and test the water chemistry in your tank. It is also recommended to dip the coral in an iodine solution to help combat this issue.

A deflated Hammer Coral may be the result of temperatures that are too high, aggression from other corals, or inconsistent water parameters. Adjusting the tank conditions and making sure they are not too close to other corals should allow your Hammer Coral to perk back up.

Where Can I Find Hammer Coral for Sale?

Hammer Corals can be bought in specialty stores or from specialty shops online that sell corals and coral fragments. They can also be bought on eBay. The cost of a Hammer Coral fragment depends on the type and size you are purchasing. The rarer a coral type is, the harder to find and therefore the more expensive it will be. Smaller, more common types can range from $10 to $60 while larger or rarer types can go into the hundreds.

Different Type of Hammer Coral

  • Gold Hammer Coral is characterized by a green body with gold T-shaped tips.
  • Purple Hammer Coral has a full body of purple with T-shaped polyps, whereas the Purple Tipped Hammer Coral has a lightly colored blue, green, or yellow body with purple only on the tips.
  • Green Hammer Coral is a full body light green color with rounded T-shaped polyps.
  • Rainbow Hammer Coral has a beautiful iridescent coloring, featuring yellow, blue, purple, and green on the stems and polyps. The polyps are a rounded T-shape.
  • Holy Grail Hammer Coral is one of the rarer types of these corals. They are often mistaken for gold hammer corals because of their similar green stems but Holy Grail Corals have a brighter yellow tip rather than the golden hue of Gold Hammer Corals.
  • Teal Hammer Coral have a bright teal T-shaped polyps with rich blue stems.
  • Rose Gold Hammer Coral is a full body pale pink or mauve color with rounded T-shaped polyps.
  • Red Hammer Coral has deep red stems with a tip that is bright red or orange red.
  • Neon Green Hammer Coral has a deep red or purple body with bright neon green rounded polyps.
  • Indo Gold Hammer Coral has a similar look to the Gold Hammer Coral with the same gold tips, but the stems are a dark purple rather than green.

Wall vs Branching Forming Hammer Coral

Care requirements for the Hammer Coral does not vary greatly based on color, however they do vary based on the type of growth formation.

Wall formations grow as one continuous skeleton along the rock it is attached to and get wider as they grow. Branching formations grow horizontally as well as vertically, growing different heads and resembling the branches of a tree. Branching formations have shown faster growth rates than wall formations. If you are looking for a slower, controlled growth the wall variety may be ideal for you.

Branching corals are also easier to frag, since you can typically find a separate coral head to split off without cutting into live tissue. With wall formations you are more likely to cut or break live tissue, leaving the coral susceptible to infection. If infection does occur, it is harder to salvage the whole wall coral as opposed to branching corals, whose separate heads can be saved before the infection spreads.

Whichever color or formation you choose, both provide a beautiful addition to any aquarium tank.

Fish Laboratory

With decades of collective fishkeeping experience, we are happy to share the fish care tips that we've picked up along the way. Our goal at Fish Laboratory is to keep publishing accurate content to help fishkeepers keep their fish and aquarium healthy.

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