One of the most common debates in the aquarium hobby is if corals need feeding, and, if so, what are their feeding habits. Some reef hobbyists will argue that corals do not need any additional food in the aquarium, while many coral enthusiasts believe that feeding corals are a must.
The hammer coral (Euphyllia ancora) is a beautiful large polyp stony (LPS) coral that will add a dramatic display to your aquarium. The most important part of coral husbandry is ensuring your hammer coral is happy and healthy, and the hammer coral is a staple coral for showing you when they are comfortable in its home.
Your hammer coral will expand its polyps to feed when it is happy inside the aquarium, which is why it is recommended to feed these types of corals.
Do Hammer Corals Need Feeding?
Many people forget that corals are animals, not plants. One thing that we have in common with corals is that we both need food to survive, and your hammer coral is no exception.
Now, hammer corals are slightly different from other LPS corals because they are not active, ravenous eaters, and while it is true that your hammer coral gets most (75%) of its nutritional requirements from aquarium lighting, your coral will grow much faster and more robustly if you occasionally feed it.
But, before we go into what to feed your hammer coral, it is important to understand how your coral gets food from light.
Your hammer coral contains microscopic algae called zooxanthellae inside its tissues, which provide the majority of its nutrition. The algae undergo photosynthesis when the lights are switched on and your hammer coral extends its polyps. This is why your aquarium lighting is crucial when caring for corals.
But, in addition to the zooxanthellae, your hammer coral can capture planktonic organisms and food particles in the water, and it can absorb dissolved organic matter for nutrition. However, unlike most LPS corals, hammer corals are not eager eaters for supplemental feeding, so there are certain foods and feeding methods you must follow.
What Do Hammer Corals Eat?
As mentioned, your hammer coral is a more subdued eater than most corals, but that doesn’t mean your coral will not love a meaty treat now and then.
Your hammer coral may only accept supplemental feedings once or twice a week, and this is totally okay! In fact, overfeeding should be avoided, not because it will harm your hammer coral, but because it will add too many organics, which is likely to cause issues with your water chemistry.
You want to select foods that offer your hammer coral high-quality proteins and amino acids. This is because, amino acids are important for your hammer coral’s growth, and for repairing their tissues if they become damaged.
Reef Tank Advisor’s Top Picks!
- Enriched brine shrimp
- Copepods
- Mysis shrimp
In addition to the above, your hammer coral can also devour larger pieces of food because it has a rather large mouth, therefore you can also feed your coral diced fish or shrimp.
As different parts of the fish have different nutritional qualities, you should cut up the whole fish to benefit your hammer coral’s health.
How To Feed Hammer Corals?
Euphyllia corals, like your hammer coral, and other LPS corals have various feeding strategies. The two most effective feeding methods are target feeding and broadcast feeding.
Precision target feeding is more popular because it reduces waste and prevents fish from stealing the food, however, if you prefer to broadcast feed your corals, that is also fine, but remember to keep a close eye on your water chemistry and siphon any uneaten food.
How To Target Feed Hammer Corals?
Target feeding is not only the most precise feeding strategy, but it is also recommended for corals that are damaged or bleached.
To target feed your hammer coral, you can use equipment such as:
- A turkey baster from your kitchen cupboard
- Julian’s Thing Multi-Purpose Tool
- Sea Squirt Coral Feeder
A step-by-step guide to target feeding
- Prepare one-third of your coral’s food by mixing it with two-thirds of aquarium water.
- Turn off any return pumps, skimmers, and wave pumps.
- Wait until the aquarium’s water flow has completely stopped.
- Fill your baster, or whichever tool you are using, with the food mix you prepared earlier.
- Gently release the food slowly, directly above your hammer corals mouth, allowing it to absorb everything.
- Remember to set a timer, so you don’t forget to turn all the systems back on.
- Once you have fed your hammer coral, turn on your powerheads/wavemakers to 5-10% intensity for around 5 minutes before turning them on full blast. This allows any leftover food to spread around the aquarium and become suspended in the water.
How To Broadcast Feed Hammer Corals?
Broadcast feeding is the less preferred method for hammer corals, but it is easier and still efficient.
A step-by-step guide to broadcast feeding
- Turn off your protein skimmer and the main pump, so that the food is not removed by the carbon media and skimmer. But, remember to leave the wave pumps on, so that the food can be evenly distributed inside the aquarium.
- Prepare your hammer coral’s food by mixing it with aquarium water and placing it in a measuring cup.
- Slowly pour the coral food near the wave pumps. If you don’t have wave pumps inside your aquarium, slowly pour the food from one side of the aquarium to the other.
- Set a timer for 30 minutes, and then turn all of your aquarium systems back on.
You can also broadcast feed your hammer coral using a dosing pump, by filling your dosing container with a weeks-worth of coral food. This is great if you know you are going away on vacation, or you can sometimes be forgetful!
How Do I Know That My Hammer Coral Is Eating?
When your hammer coral is feeding, each tentacle will fully extend. During feeding time, your hammer coral can stretch to become two to three times their usual/relaxed size!
You will also see your hammer coral’s mouth opening when it detects the food.
How Often Should I Feed My Hammer Coral
As your hammer coral is photosynthetic, you only need to feed your coral 2-3 times a week, allowing plenty of time before feedings to prevent fluctuations in your water parameters.
Upon testing the water quality, your water parameters should be within the following ranges:
- Temperature: 72° – 78 °F
- pH: 8.1 – 8.3
- Salinity: 1.024 – 1.026
- Alkalinity: 8 – 12 dKH
- Nitrates: <10 ppm
- Phosphates: <0.10 ppm
- Calcium: 350 – 450 ppm
- Magnesium: 1200 – 1350
How Much Lighting Does My Hammer Corals Need?
Hammer corals require moderate lighting, with a PAR range of 80-150 for the zooxanthellae to undergo photosynthesis to provide enough nutrition for your coral. Subdued lighting also encourages your hammer coral to extend its polyps further and show off their unique colors and growth morphs.
If your lighting is too high, your hammer coral will expel the zooxanthellae, leaving them without 75% of their nutritional needs, and therefore your coral will start bleaching due to lack of pigmentation.
To control your lighting levels, it is highly recommended you invest in a PAR meter. If you are not quite there yet, do not worry, as you can hire one from your local fish store or online.
Summary
One of the biggest debates when keeping corals in aquariums is if corals should be fed. While it is true that corals get most of their nutrition from symbiotic algae called zooxanthellae, most corals, in particular LPS corals like Euphyllia types, will benefit from additional supplemental feeding.
Coral foods come in different types and sizes, so check what foods are recommended for your particular coral. Hammer corals have large mouths, so pellet or powdered foods that are rich in proteins and amino acids (for example mysis/brine shrimp) make the perfect treat for your coral.
Hammer corals are subdued eaters, but once you wave some food near their mouth, they will open up and fully extend their polyps, taking part in a feeding frenzy!
