Feeding live corals in a reef aquarium is a combination of art and science and using the best coral food is essential.
Most coral research is conducted in the ocean, in the natural reef formations.
We use this information to make our reef tanks as close as possible to the conditions found on tropical coral reefs.
Aquarists keeping and fragging corals are focused on giving their corals what they need to grow and thrive.
Growth requires energy.
This energy comes from food.
We’ll look at the nutritional needs of corals and how to feed them in a reef aquarium .
Best Coral Food
Last update on 2023-03-20 / Affiliate links / Images from Amazon Product Advertising API
Understanding coral nutrition
There are two basic categories of corals.
Hermatypic corals contain living algae within their tissue.
These algae get energy from sunlight and release organic nutrients into the coral tissue.
The specialized algae are called Zooxanthellae (zo-zan-THEL-ee). These algae, living inside the coral, provide a portion of the energy the coral need to survive.
Small polyp stony (SPS) and large polyp stony (LPS) corals along with some soft corals contain zooxanthellae algae.
The algae also give bright coloration to the coral tissue.
SPS and LPS corals especially require fairly bright light in order for the algae to thrive and produce energy for the corals.
However, these corals need more energy than the algae can supply. Studies show that coral use other food sources to drive new skeletal growth, repair damaged tissue and sexual reproduction.
In nature and in the aquarium, corals use their polyps to capture free-floating plankton, fish eggs, algae and other energy sources that can be captured with their tentacles.
Corals also use sticky mucus nets to capture bacteria and pieces of organic matter.
Coral colonies obtain energy from all these sources along with elemental trace elements like calcium and magnesium from the water.
Marine biologists estimate that hermatypic corals get their energy:
Ahermatypic corals. Unlike hermatypic coral species, ahermatypic corals do not have living algae inside their tissues.
All of the nutrition must be captured by the polyps, mucus nets and adsorbed directly from the water.
Ahermatypic corals include tree corals and gorgonians.
These corals are too difficult for most reef aquarists to keep alive. This may be due to the difficult feeding requirements of these species.
This is why the SPS and LPS are the most common corals among aquarists
Feeding corals in the aquarium
In nature corals consume microscopic crustaceans, called zooplankton.
The tiny shrimp-like creatures are packed with nutrition like fatty acids, enzymes and trace elements.
Public aquariums and commercial fragging operations often raise live zooplankton to feed to their corals.
The cultures require first growing algae to feed to the zooplankton.
The crustaceans eat the algae, which is converted to concentrated fatty acids and other essential nutrients.
The corals capture the zooplankton with their tentacles, pushing the them into the polyps where digestion and nutrient adsorption takes place.
An easier live food to raise are baby brine shrimp.
A web search will provide the steps necessary to hatch brine shrimp eggs at home.
The baby brine shrimp are added to the reef tank or target fed directly into the corals.
Large polyp stony (LPS) corals will often take in a piece of shrimp or other meaty food placed directly on the polyps.
The polyp will extend its tentacles and pull the piece of meat into its mouth.
Feeding prepared coral foods - Targeted Feeding
Commercially prepared coral foods contain proprietary formulas but we know that many contain essential vitamins, amino acids, trace elements, algae and zooplankton.
Some more complex formulas contain oyster eggs and a variety of whole zooplankton like copepods, rotifers and brine shrimp.
Corals can sense or “taste” food that is in the water or in contact with the coral tissue.
Rather than pour a lot of food and nutrients into the water, target feeding places small amount of food right at the mouth of the corals.
This technique greatly reduces the amount of food missing the corals and polluting the water.
Many reef keepers also add inorganic nutrients to the water, in the form of calcium, magnesium, iodine and strontium supplements.
These essential elements are used by the corals in building their skeleton and new tissues.
When to feed corals
Zooplankton come out of hiding and start foraging on the live rock. Ocean currents suspend the plankton, allowing the coral polyps to capture it.
You can feed any time but also try to feed your corals during low light, evening conditions.
Turn off the return pump so the food does not get sucked into the overflow or filter system. Remember to switch on your pumps back after feeding!
Can I feed too much?
Coral feeding is relative to the size and number of corals in your aquarium.
You may have a large tank with a lot of gallons but only a few corals.
Obviously, you would not feed based on gallons of water.
Adding too much food can stimulate algae blooms and nitrate spikes.
Some aquarists feed several times a month, others feed every day.
Keep a close watch on water quality and clarity.
Your protein skimmer may produce more skimmate in response to the food in the water and the increased metabolism of the corals and other filter feeders.
Part of the adventure of a reef aquarium is discovering how the corals respond to feeding.
Over time you’ll learn what foods give the best results and how often you need to feed the reef.
Using a target feeder
While pouring in a coral food simulates a plankton bloom, a lot of the food particles can get trapped in the live rock or removed by the filter system and protein skimmer.
You may also find times where you want to feed a certain food to specific corals.
A target feeder is the ideal tool to put food exactly where you want it.
Julian’s Thing target feeder is a popular feeding tool and is available on Amazon.
It is designed to make it easy to put the food just where you want it.
Use Julian’s Thing to feed corals, anemones and even seahorses and other timid or slow-moving fishes.
The pumping action can also be used to blow sand away from coral colonies.
The Top prepared corals foods
There are a variety of prepared foods designed for feeding corals and other marine life that need tiny food particles.
We took a look at the most popular brands and types of coral foods and came up with our list of best coral foods for reef aquarists.
Reef Roids was originally developed for hard-to-feed captive Goniopora corals.
Experimentation in reef aquariums revealed that all filter-feeding invertebrates liked the food.
Instead of using ordinary fish meal as a protein source, Reef Roids contain a proprietary blend of naturally nutritious high-protein plankton.
The precise-sized 150-200 micron particles are recognized as food by all types of filter-feeding corals.
Corals capture the particles and draw them into the polyps for digestion and assimilation of the proteins, lipids and trace elements.
Each particle is also rich in astaxanthin, a natural color-enhancing carotenoid found in zooplankton.
These nutritional and natural color enhancing ingredients stimulate vigorous coral growth with more intensive coloration.
Reef Roids can be target fed, broadcast into the water or blended with other foods.
Coral Frenzy is a dry prepared formulation for corals, sponges, clams and other filter-feeding invertebrates.
It can also be eaten by small nano reef fish.
The ingredients of the food formula are provided by the manufacturer and include fish protein, oyster larvae, salmon eggs, Dunaliella salina, Schizochytrium, rotifers, copepods, daphnia, spirulina algae and Haematococcus pluvialis. Dunaliela is a marine micro-algae rich in color-enhancing carotenoids.
Schizochytrium algae are rich in fatty acids.
Haematococcus pluvialis is a green algae rich in color-enhancing astaxanthin.
The powder is mixed with aquarium water to wet the particles.
The slurry can be target fed or poured into an area of high flow for dispersion into the aquarium.
Two Little Fishies Marine Snow
In the reef, “marine snow” is the term for floating microscopic food particles composed of algae cells, zooplankton, bacteria cells and other organic particles glued together with natural, sticky polymers.
These “ingredients” form a nutritious matrix that drifts through the reef like snowflakes.
Marine snow is a dense high-energy food source formed in the upper layers of the ocean.
Marine snow is captured by filter feeding invertebrates like SPS and LPS corals, sponges, clams and anemones.
Two Little Fishies Marine Snow is a liquid suspension composed of marine based planktonic algae, zooplankton and dried seaweed powder.
The microscopic particles range from 20 to 150 microns.
Marine Snow mimics the drifting planktonic foods found in coral reefs. Each particle of Marine Snow is a nutritious packet of vitamins, trace elements, enzymes and fatty acids.
Marine Snow is fed by adding directly into the water flow or through target feeding.
AFB Decapsulated Brine Shrimp Eggs, for Corals, Fry, Babies
AFB decapsulated brine shrimp eggs are an all-natural source of nutrition for corals, clams, reef shrimp, and small fish.
Note that this product in not regular unhatched brine shrimp eggs. They cannot be hatched.
The eggs are harvested from the Great Salt Lake in Utah.
The eggs are washed in chlorine bleach to remove the hard egg capsule from the embryonic shrimp cyst.
The empty shell is separated from the nutrition-packed cyst.
The cysts are rinsed and packed in plastic bags.
Because no energy was used to hatch out of the eggs, the cysts retain their full nutritional make-up including lipids, amino acids, and enzymes.
Decapsulated brine shrimp cysts are richer in nutrition than newly hatched live baby brine.
AFB decapsulated brine is an easy way to get the nutritional benefits of live baby brine but without the need to continually hatch the shrimp eggs.
OceanMagik Live Phytoplankton Blend
Algae Barn’s OceanMagik live phytoplankton blend is a live culture of four algae plankton species.
The product contains Nannochloropsis, a 1-5 micron yellow/green algae; Isochrysis galbana, a 10-14 micron golden-brown algae; Tetraselmis green algae 6-10 microns in size and Thalassiosira weissflogii, a green brown algae in the 5-32 micron range.
The wide range of algae cell sizes covers the filter feeding spectrum of corals, copepods, sponges, shrimp and small reef fish.
One of the benefits of adding OceanMagik is that the live algae removes phosphate and nitrate from the water, reducing the chances of hair algae growth.
The live algae are also consumed by copepods living in the live rock.
Copepods are a natural food source for corals and marine fish. Mandarin fish, popular with reef aquarists, require a steady supply of live copepods and amphipods to remain alive in captivity.
OceanMagik is formulated to feed the copepods in your reef tank, which in turn keeps the natural “pod population” thriving for the Mandarins and other marine life to consume.
Final thoughts on coral foods
While some reviews weed out the low-performing products, all of these corals foods are top-notch, proven winners.
The key thing to remember when feeding corals is that no two reef tanks are alike.
The make up of coral species, the natural feeding behavior and even the live food population that live in the tank can play a role on which foods work best.
Keeping corals in captivity is easier than ever but there is no one perfect food for all corals. That’s why we recommend experimenting with all of these foods.
Overall, we like natural and live foods.
OceanMagik makes a lot of sense because it is eaten directly by corals and feeds the in-tank copepod population.
This balances the reef tank and “farms” live pods for coral consumption.
Reef Roids is a manufactured food but has proven track record in reef tanks.
The prepared foods are especially easy for a family member to add or a non aquarist when you are away on business or vacation.
Try them all and watch your corals.
You’ll know which foods cause your corals to color-up and grow within a month or so.
In no time you’ll have a feeding regimen worked out that maximizes growth and vibrant coloration.