𝐇𝐨𝐰 𝐭𝐨 𝐅𝐞𝐞𝐝 𝐂𝐨𝐫𝐚𝐥𝐬: 𝐖𝐡𝐚𝐭 𝐓𝐡𝐞𝐲 𝐄𝐚𝐭, 𝐇𝐨𝐰 𝐎𝐟𝐭𝐞𝐧, 𝐚𝐧𝐝 𝐇𝐨𝐰 𝐌𝐮𝐜𝐡

As a reminder, I write these articles for fun and to help people learn and avoid the mistakes I made. If I missed something let me know and I can add it to the article. 

-Tamara

Introduction

There are few things in reef keeping more satisfying than watching a hungry LPS coral eat.

You drop a little piece of mysis on an Acan. The feeding tentacles grab it. The tissue folds inward. Five minutes later, it’s gone. Success. You fed your coral.

Then you look three inches to the left at your leather coral. Nothing. No tentacles. No mouth swallowing. No dramatic response. So… does that coral not eat?

This is where coral feeding gets confusing.

Some corals will practically grab dinner out of your hand. Others capture particles so small you’ll never see it happen. Some rely heavily on photosynthesis but still benefit from other food sources. Some can capture zooplankton, bacteria, dissolved organics, and tiny suspended particles. And then there are non-photosynthetic corals that really do depend on you to keep them alive.

Corals are not nutritionally identical just because we lump them all under the word "coral." That’s why I don’t believe in a single coral-feeding schedule.

I personally target-feed my larger LPS corals and anemones. I broadcast-feed much of everything else. I use phytoplankton and rotifers when I have them. Sometimes I feed after dark. Sometimes I have to cover an LPS while it eats because feeding the fish first does absolutely nothing to convince them that the giant chunk of food sitting on the Acan belongs to the Acan.

My approach changes depending on the tank. Yours should too.

By the end of this article, I want you to understand what different corals can eat, which foods make sense for which corals, how often I would start feeding them, how much to offer, how to tell if the coral is actually eating, and when feeding more is doing more for your algae than it is for your coral.

Because the goal isn't to feed the most. The goal is to feed intentionally.

Do Corals Actually Need Food If They Have Light?

Ask ten reefers how often to feed corals, and nine will argue. The tenth is just standing over their tank at midnight with a pipette and seven kinds of frozen food. I’ve been that tenth person. I’ve also been the first. Here’s what I actually do now.

Most reef-building corals contain photosynthetic dinoflagellates, often called zooxanthellae. These symbionts live inside the coral’s tissues and produce carbon-rich compounds that feed the host. Under good conditions, that photosynthesis can satisfy most, and in some cases, potentially all of the coral’s respiratory carbon needs.

But here’s the part people miss:

Energy is not the entire nutritional story.

Corals also need nitrogen, phosphorus, amino acids, and other materials to build proteins, tissue, reproductive products, enzymes, and new biomass.

Research increasingly describes photosynthetic corals as mixotrophs. That means they get nutrition through multiple pathways, photosynthesis from their symbionts, plus heterotrophic feeding, dissolved materials, plankton, and internal nutrient recycling. How important each pathway is varies wildly by species and conditions.

So do I think most corals get absolutely everything they need from light? No.

Do I think every coral in your aquarium needs a pipette full of food three nights a week? Also no.

Welcome to reef keeping. We couldn’t possibly make this easy.

The One Rule I Care About More Than Feeding Frequency: Food Size

If you remember one thing from this article, make it this: Your coral should not have to fight its dinner. Bigger food does not automatically mean better nutrition.

I sometimes see people place an enormous chunk of shrimp onto a fleshy LPS and then proudly watch the coral spend the next half hour trying to swallow it.

That isn’t a successful feeding response. That’s a project. Often if you watch the coral long it enough it will have to spit it out if it can't digest it.

Corals have evolved different prey-capture strategies. Some capture relatively large zooplankton. Others specialize in tiny suspended particles. They use tentacles, nematocysts, mucus, and other structures to capture everything from larger zooplankton all the way down to microscopic plankton and bacteria.

Match the food to the animal. For a large fleshy LPS, a small piece of mysis or a pellet is perfectly appropriate. For SPS, think much smaller. For filter and suspension feeders, think smaller still.

My rule: When you're unsure, start smaller. A coral can capture another small meal later. It cannot ask you to remove the shrimp steak you just dropped on its face.

How Much Should You Feed?

I don’t measure coral food by teaspoons per gallon. I watch the coral.

For target feeding: I offer enough that the coral can capture and consume a reasonable meal without food sitting around afterward.

For broadcast feeding: I want food dispersed throughout the water column without turning the aquarium into soup.

If a significant amount of food is settling into the rocks, coating the sand, entering the overflow untouched, or sitting on coral tissue uneaten, you're probably adding more than the animals are using.

Corals do not need to eat until they can't possibly fit anything else inside themselves. Small to moderate meals work just fine.

Most photosynthetic corals also do not need direct feeding every single day. The goal is not: How much food can I get this coral to swallow?

The better question is: How much useful nutrition can I provide without creating unnecessary waste?

Your nitrate and phosphate levels will tell you when the balance is shifting. If both start climbing after you increase feeding, pay attention. I have separate articles that go much deeper into nutrient management, so I won't turn this one into a chemistry lesson.

My Trick Before Target Feeding: Scent the Water

I’ve done this for years. About 15 to 20 minutes before I target-feed, I put a small amount of frozen fish food into the aquarium. I call it "scenting the water". Then I wait.

Often, feeding tentacles start emerging before I’ve target-fed anything. That response isn’t magic, corals can detect chemical cues associated with prey, and those cues trigger feeding behaviors before actual capture happens.

By the time I come back with the coral’s meal, I don’t have to convince a closed coral that dinner is happening. The restaurant is already open.

You don’t have to do this, but with fleshy LPS, I’ve found it makes target feeding easier and considerably more entertaining.

Coral Category Breakdown

SPS

SPS corals are probably where the "light is food" idea persists the most. Yes, photosynthesis is enormously important. But SPS corals are still animals capable of heterotrophy.

Research has shown that reef-building corals can capture zooplankton, pico- and nanoplankton, particulate organic material, bacteria, and dissolved organic compounds—though the contribution of each source varies substantially among species.

For SPS, I prefer fine suspended foods over trying to target every polyp individually.

Useful options:

• Fine powdered coral foods

• Rotifers

• Very small zooplankton

• Fine suspended frozen foods

Broadcast feeding makes more sense here. I start around one to three times per week, depending on stocking, nutrient levels, and how much food is already entering the system. Don’t assume more food equals faster growth. It doesn’t work that simply.

Euphyllia

Hammer, frogspawn, and torch corals are capable of capturing meaty foods, and watching them eat is incredibly satisfying.

I use appropriately sized:

• Mysis

• Chopped marine foods

• Small pellets

• Other small meaty marine foods

Start around once or twice per week. You don’t need to feed each head an enormous chunk. If the food is easy to capture and move toward the mouth, you've done your job. If the coral is still wrestling with it 20 minutes later, go smaller next time.

Acans and Micromussa

If you want to show a beginner what coral feeding looks like, this is one of my favorite groups. Many Micromussa, including what we still casually call Acans, produce an obvious feeding response. After scenting the water, you may see tentacles extending around individual polyps before you even start feeding.

I like:

• Mysis

• Small pellets

• Finely chopped marine foods

• Small pieces of other appropriate meaty foods

I generally start around one to three small meals per week. And this brings me to one of my favorite reefing tricks.

Sometimes you have to put your coral in "fish jail". Okay, technically you're protecting the coral from the fish, but fish jail sounds funnier.

I have tanks where fish will steal food directly from an LPS before it has time to swallow. In those tanks, I target-feed the coral and temporarily place a perforated cover, feeding dome, or appropriate container over it. I like to use the top if 2L soda bottles for most of my sand dwellers, and I cut small slits into it.

Water can still move through. The coral gets time to eat. And the fish stand outside looking deeply offended by this violation of their constitutional rights. Remove the cover once the coral has ingested the food.

Scolymia, Homophyllia, and Trachyphyllia

Large fleshy solitary LPS are built to capture food, and they can produce spectacular feeding responses. But their large size is exactly why people tend to overdo it. A huge coral does not need a huge piece of shrimp.

Start with:

• Mysis

• Small pellets

• Finely chopped marine foods

• Appropriately sized pieces of marine flesh

Usually one or two moderate feedings per week is a perfectly reasonable place to begin in a typical mixed reef.

Watch what happens. If the coral grabs the food and readily moves it into the mouth, excellent. If it captures the food, repeatedly drops it, spends forever trying to engulf it, or eventually spits it back out, that meal was probably too large or inappropriate.

Zoanthids and Palythoa

Zoanthids are another group where feeding responses vary enormously. Some readily capture suspended particles. Others seem profoundly unimpressed by everything you offer them.

Fine particulate foods and small zooplankton are generally more appropriate than trying to balance a mysis shrimp on every polyp. You can gently broadcast or lightly target-feed once or twice a week if you want to experiment. But if your zoanthids are growing beautifully in a well-fed reef without dedicated feeding, I wouldn’t invent another chore simply because an article told you to.

Including this one.

Mushrooms

Mushrooms are surprisingly variable feeders. Some will readily fold around food and transport it toward the mouth. Others show very little interest in direct feeding.

Small meaty particles or appropriately sized pellets can work well for species that demonstrate a strong feeding response. Again, let the animal tell you.

If the mushroom repeatedly captures and consumes the food, great. If you're repeatedly placing food on it only to watch the current carry it away five minutes later, stop trying to force the relationship.

Leather Corals

Now we get into animals that confuse people because there isn't a giant mouth waiting for a mysis shrimp. Leather corals derive substantial nutrition through their photosynthetic symbiosis and can also interact with very fine particulate and dissolved nutritional sources.

Research comparing soft and hard corals has demonstrated that both can assimilate dissolved nitrogen sources, though nutritional strategies differ among species.

I don't routinely target-feed leather corals with chunks of food. Fine suspended foods entering the aquarium, normal fish feeding, dissolved nutrients, and the tank's existing food web all contribute to their nutrition. If you're broadcast-feeding the reef, they're already living in the same water. You don't need to chase them around with a turkey baster.

Xenia and Similar Soft Corals

Xenia is a great example of why "I don't see it eat" and "it doesn't obtain nutrition" are not the same statement. Xenia relies heavily on its photosynthetic symbiosis and does not feed like an Acan.

Research on Xenia umbellata has shown that food sources can affect its physiology—but that doesn’t mean you need to target-feed it. I don't target-feed my Xenia.

If it is growing, pulsing, maintaining good tissue, and generally behaving like Xenia tends to behave—which usually means plotting to occupy every available square inch of your aquarium—I leave it alone.

Photosynthetic Gorgonians

This group deserves its own category because "gorgonian" tells you almost nothing about feeding requirements. Photosynthetic gorgonians receive substantial nutrition from their symbiotic algae but can also capture suspended particles.

Fine foods make the most sense:

• Rotifers

• Fine zooplankton

• Small suspended particulate foods

• Appropriate powdered foods

Broadcast feeding two to three times per week is a reasonable starting point for many commonly kept photosynthetic species—then adjust according to species and tank conditions.

Polyp extension is useful to watch here. You want food moving through the colony where the polyps actually have an opportunity to capture it.

Non-Photosynthetic Gorgonians

If your gorgonian is non-photosynthetic, everything changes. I want to be very clear here because these animals are sometimes sold to people who have absolutely no idea what they just bought.

Non-photosynthetic gorgonians cannot rely on photosynthetic symbionts to cover the nutritional gap.

Food isn't supplemental husbandry. Food is life support. Depending on the species, successful care can require daily—or even multiple—feeding opportunities per day using appropriately sized planktonic foods.

That means:

• More food entering the aquarium

• More nutrient-management pressure

• More attention to particle size and flow

• More time

• Considerably less room for "I'll feed it tomorrow."

Some NPS gorgonians are gorgeous. Some are also completely inappropriate for a hobbyist who wants a low-maintenance reef. Know what you're buying.

Other Non-Photosynthetic Corals

The same warning applies broadly to NPS corals. Do not take the feeding schedule for your Euphyllia and apply it to an animal that derives essentially no nutritional support from photosynthesis.

Different NPS species specialize on different particle sizes and food sources, so there is no responsible universal NPS feeding schedule.

• Some require extremely frequent feeding.
• Some require specialized foods.
• Some are difficult to maintain long-term even in experienced hands.

This is one category where I strongly recommend researching the exact species before purchase. Not after it starts losing tissue. Before.

Anemones: Not Corals, But We're Talking About Them Anyway

Anemones are not corals, but they are cnidarians and they inevitably end up in every coral-feeding conversation, so I'm including them. Many commonly kept photosynthetic anemones receive substantial energy through their Symbiodiniaceae while also being very capable predators. I personally target-feed mine.

Depending on the species and size, I use appropriately sized:

• Mysis

• Shrimp

• Fish

• Other marine-origin meaty foods

For many commonly kept photosynthetic anemones, one or two modest meals per week is plenty as a starting point, especially in a tank where they're also benefiting from normal fish feeding. Please do not give your anemone half a grocery-store shrimp because it has a large mouth.

Again:
Small meal.
Easy to ingest.
No wrestling match required.

Phytoplankton: Useful, Useless, or Somewhere in Between?

Welcome to another reefing topic nobody agrees on.

I want to be very clear that not every experienced aquarist believes routine phytoplankton dosing provides a meaningful direct benefit to corals in a typical reef aquarium.

Part of the disagreement comes from lumping all corals together.

Different corals have different capacities to capture different plankton sizes, and adding phytoplankton to an aquarium can also have indirect effects by supporting other members of the food web.

Research has demonstrated phytoplankton and very small planktonic organisms as nutritional sources for at least some coral species—but that doesn’t mean every coral in your aquarium is directly eating every phytoplankton species you pour in.

I use it. I think it can have a place in a reef-feeding strategy. I don't consider it mandatory. And because I have an entire phytoplankton series, I'm going to stop there before this article becomes a book.

Rotifers

Rotifers are tiny zooplankton and are useful when you need something between microscopic phytoplankton and larger foods like mysis. Their size makes them particularly useful for broadcast-feeding corals with small polyps and for some suspension feeders.

I feed them when I have them available. They aren't something every reefer needs to culture or purchase constantly, but they're a useful tool when you're trying to provide a range of prey sizes.

Powdered Coral Foods: A Little Means A Little

I like powdered coral foods. They're convenient, they provide very small particles, and they make broadcast feeding easy. They're also incredibly easy to overfeed. A little goes a long way.

You do not need to create a dense cloud that makes the aquarium look like someone dumped flour into it. Start with substantially less than your emotional instincts tell you to use.

• Watch the coral response.
• Watch what settles.
• Watch nitrate and phosphate over the following weeks.

Increase only if you have a reason.

Pellets

Pellets are underrated for larger-polyped corals. They're easy to portion, easy to target, nutritionally consistent, and much easier to control than dropping random chunks of seafood into the tank.

The trick is size. A small pellet that an Acan can grab and swallow easily is useful. A giant pellet sitting half inside a coral's mouth for an hour isn't. Pellets also make it easier to know approximately how much you're feeding from week to week.

Frozen Foods

Frozen foods are probably the most versatile category in my feeding routine. Depending on particle size, they can feed fish, LPS, anemones, and suspension-feeding organisms.

Mysis, copepods, rotifers, plankton blends, and finely chopped marine foods all have different applications.

One of the reasons I like frozen foods is that the thawed liquid releases chemical cues into the aquarium—exactly why I use a little frozen food to "scent" the water before target feeding.

What About Fish Food and Fish Poop?

Your corals do not live in a nutritional vacuum until you arrive with a pipette. Every time you feed your fish, food particles enter the water. Tiny fragments escape. Fish process food and excrete nutrients back into the aquarium. Bacteria process organic material. Planktonic organisms consume and recycle nutrients.

Your reef is a food web. This is why two people can keep the exact same coral and have completely different experiences with supplemental feeding. A heavily stocked aquarium with ten well-fed fish may already deliver substantial particulate and dissolved nutrition throughout the day.

A lightly stocked SPS aquarium with two tiny fish and aggressive nutrient export is an entirely different nutritional environment. That's why I keep coming back to the same advice: Feed the tank you actually have.

Target Feeding Versus Broadcast Feeding

I use both.

Target Feeding

I target-feed larger LPS and anemones. For target feeding, I usually turn the pumps off or substantially reduce flow. I want the food to reach the coral and stay there long enough to be captured. Use a pipette, turkey baster, feeding tube, or similar tool.

And please be gentle. You are delivering dinner, not pressure-washing the coral. Place the food close enough for the feeding structures to capture it. Then back away and let the animal do the rest.

Broadcast Feeding

When broadcast feeding, I generally turn off the protein skimmer and reduce export while keeping some circulation in the aquarium. Depending on the tank, I may turn off the return pump while leaving powerheads running.

The goal is to keep food circulating past feeding surfaces rather than immediately sending it down the overflow and into filtration. I don't want completely stagnant water. I want controlled circulation. Once the feeding period is finished, normal circulation and filtration go back on.

Night Feeding: My Favorite Time to Feed

I love feeding corals at night. Partly because many corals naturally increase feeding activity after dark—polyp extension associated with heterotrophic feeding commonly increases at night in many species.

But mostly? Because it's one of my favorite ways to experience a reef tank.

The fish settle down. Tentacles appear that you barely see during the day. Tiny animals start moving through the rock. Corals that looked completely passive six hours earlier suddenly look predatory. It feels like somebody switched aquariums while you weren't looking.

That said, you do not have to feed at night.

Corals can respond to repeated feeding schedules and chemical cues. Many aquarium corals will readily extend feeding structures during the day once they associate that period with food. If Tuesday at 7 p.m. works for your life, feed Tuesday at 7 p.m.

A feeding schedule you actually maintain is considerably more useful than the theoretically perfect schedule you abandon after two weeks.

How Do You Know Your Coral Is Actually Eating?

This is important. A reaction is not always ingestion. Food touching coral tissue and making the coral contract does not necessarily mean the coral ate it.

Look for:

1. Tentacle Capture: Feeding tentacles or polyps actively hold the particle rather than letting it drift away.
2. Movement Toward the Mouth: With many LPS, you'll actually see the food gradually transported toward the mouth.
3. Tissue Envelopment: Fleshy corals may fold tissue around prey.
4. Successful Ingestion: The food disappears into the mouth rather than being released ten minutes later.
5. Repeatable Response: If the same coral consistently responds to the same appropriately sized food, that's useful information.

This is where observation becomes more valuable than somebody else's feeding chart.

A Short Note on Amino Acids

I personally use amino acids. There's legitimate biological reasoning behind it—corals can acquire dissolved free amino acids, and they participate in protein synthesis and nitrogen metabolism within the coral holobiont.

But I don't consider an amino-acid supplement a replacement for particulate feeding. And I don't consider it mandatory for every reef. I have a separate article, Amino Acid, Carbohydrate, and Vitamin Dosing in Reef Tanks, where I go much deeper. For Coral Feeding 101, that's enough.

The Overfeeding Problem

If feeding is good, more feeding must be better. No.

That's why we need algae articles. The biggest problem with coral feeding usually isn't that your coral ate too much dinner. It's everything that didn't get eaten.

Excess food becomes organic material that bacteria and other organisms process. Ultimately, increased feeding can contribute to rising nitrate and phosphate and place additional demand on your nutrient-export system.

Signs you're probably overdoing it:

• Food consistently settling uneaten

• Nitrate or phosphate trending upward after increasing feeding

• Increased nuisance algae

• Heavy bacterial films

• Corals repeatedly rejecting food

• Feeding because the calendar says so even though the animals aren't responding

Reduce the portion before you eliminate feeding altogether.

Often the solution isn't: Stop feeding. It's: Feed less.

Myths

1. Photosynthetic corals don't need food. Photosynthesis can provide an enormous portion of a coral's carbon and energy, but coral nutrition is considerably more complicated than light alone. Many corals combine autotrophy with heterotrophic and dissolved nutrient acquisition.

2. More feeding means faster coral growth. Nutrition can support growth, but growth also depends on light, chemistry, temperature, flow, species, health, and nutrient availability. Extra food that isn't used is just extra nutrient input.

3. If the coral grabs the food, the size is fine. Capture is step one. The coral still has to ingest and digest it.

4. Every coral needs phytoplankton. Different coral species utilize plankton differently. Phytoplankton may also support the broader reef food web. I use it, but I wouldn't call routine phytoplankton dosing mandatory for every reef.

5. You need bottled coral food to feed corals properly. Your aquarium already contains food pathways. Fish food, plankton, microorganisms, particulate organic material, dissolved nutrients, and fish waste all contribute to the nutritional environment. Commercial coral foods can be useful. They are tools. They are not magic.

6. Coral feeding has to happen at night. Many corals naturally feed more actively after dark, but aquarium corals can respond to regular feeding cues. Feed when you can do it consistently.

Quick-Reference Feeding Chart

Use this as a starting point—not as law.