What you feed your corals depends on the type of coral you keep. Photosynthetic corals get most of their energy from the symbiotic algae living in their tissue, but they still benefit from supplemental feeding with tiny planktonic foods. Non-photosynthetic corals rely entirely on food you provide and need to eat daily, sometimes multiple times a day. Getting the food type, particle size, and delivery method right for your specific corals makes a real difference in growth and coloration.
How Corals Get Their Energy
Most corals kept in reef tanks are photosynthetic. They host microscopic algae called zooxanthellae in their tissue, and these algae produce sugars through photosynthesis that can cover up to 100% of the coral’s daily energy needs. That’s why lighting is so critical in a reef tank. But “can cover” doesn’t mean corals thrive on light alone. In the wild, corals also capture zooplankton, absorb dissolved organic matter from the water, and consume bacteria. Supplemental feeding fills nutritional gaps that photosynthesis can’t, particularly for protein, nitrogen, and the amino acids corals need for tissue growth and skeletal development.
Soft corals and hard corals handle nutrition differently. Hard corals (both SPS and LPS) tend to rely heavily on their algal symbionts for nitrogen, absorbing dissolved forms directly from the water at rates up to 10 times higher per unit of tissue than soft corals. Soft corals lean more on capturing planktonic prey to meet their nitrogen needs. This distinction matters when you’re choosing foods: soft corals often respond better to particulate foods drifting through the water, while hard corals benefit from both dissolved supplements and solid food.
What to Feed SPS Corals
Small polyp stony corals like Acropora and Montipora have tiny mouths and can only capture very small particles. Rotifers in the 50 to 200 micron range are ideally sized for SPS polyps and are the most reliably captured live zooplankton by small-polyp species. Powdered coral foods with particles in the 50 to 300 micron range also work well. Phytoplankton, while not a major direct food source for most SPS, supports the growth of copepods and other microfauna in your tank that SPS corals then capture naturally.
SPS corals also absorb amino acids directly from the water column, and dosing amino acids can noticeably improve tissue density and coloration. Amino acids like glutamine support tissue growth and cell repair, while aspartic acid plays a role in skeletal calcification. If you dose amino acids, do it at night. Many corals absorb them more efficiently when their polyps are extended after lights out.
For nutrient levels, SPS corals do best with nitrates between 1 and 5 ppm and phosphates between 0.01 and 0.05 ppm. These are tight ranges, so if you’re feeding regularly, monitor your water and adjust your protein skimmer and water changes accordingly.
What to Feed LPS Corals
Large polyp stony corals like Euphyllia (torch, hammer, frogspawn), Acanthophyllia, and brain corals have much bigger mouths and can handle meatier foods. Mysis shrimp are the go-to choice and can be target fed two to three times a week. Chopped raw shrimp, scallops, and frozen food blends designed for reef tanks all work. Many hobbyists use a mix of frozen foods including brine shrimp, fish roe, and commercial blends, broadcasting them into the tank daily and target feeding individual corals a couple times per week.
LPS corals are more tolerant of elevated nutrients than SPS. They handle nitrates in the 2 to 10 ppm range and phosphates up to 0.1 ppm without issues, giving you more room to feed generously without destabilizing your water chemistry.
What to Feed Soft Corals
Photosynthetic soft corals like Xenia, zoanthids, and leather corals are generally the least demanding feeders. They benefit from broadcast feeding with fine particulate foods, phytoplankton, and the microfauna naturally present in a well-established tank. Because soft corals rely more on capturing planktonic prey for their nitrogen, regular broadcast feeding with a fine coral food helps them thrive beyond what light alone provides. Soft corals tolerate the widest nutrient range: nitrates from 5 to 20 ppm and phosphates up to 0.2 ppm.
What to Feed Non-Photosynthetic Corals
Non-photosynthetic (NPS) corals like sun corals, carnation corals, and certain gorgonians have no symbiotic algae. Every calorie they burn must come from food you provide, which makes them dramatically more demanding than their photosynthetic relatives.
As a baseline, NPS corals should be fed daily with at least one substantial feeding session where you saturate the water with planktonic food or target feed each coral thoroughly. Most experienced NPS keepers find that two to three feedings per day produces much better results. Small, frequent feedings outperform one large dump of food.
The food mix should span a range of particle sizes. Live rotifers are excellent small zooplankton for filter-feeding NPS species. Live copepods like Tisbe or Apocyclops work well for species with larger polyps. Baby brine shrimp, cyclops, and fine powdered coral foods round out a solid rotation.
Species-Specific NPS Needs
Sun corals (Tubastraea) are the most forgiving NPS corals. Each polyp should be target fed a few times a week with nutrient-dense foods like mysis shrimp soaked in vitamins. Red “chili” corals do well with fine zooplankton (baby brine shrimp, rotifers, cyclops) fed at least every other day, ideally daily. Non-photosynthetic gorgonians like red and yellow finger varieties need daily broadcast feeding with a fine food mix and will also accept larger items like brine shrimp.
Carnation tree corals (Dendronephthya) sit at the extreme end. Many people who have kept them long-term feed the tank heavily every two to three hours or run a near-continuous drip of plankton. A single carnation coral may need to capture tens of thousands of food particles per day. They require extremely fine food: nanoplankton, bacterioplankton, rotifer-sized prey, and colloidal particles sometimes called “reef snow.” These corals are not recommended for beginners.
Broadcast Feeding vs. Target Feeding
Broadcast feeding means adding food to the water column and letting it disperse throughout the tank. It’s the easiest daily method and works well for SPS corals, soft corals, and filter-feeding NPS species. To do it effectively, turn off your protein skimmer and main return pump so the food isn’t immediately removed. Leave wave pumps on at reduced flow so food distributes evenly without blowing the mucus layer off feeding corals. Pour the food near a wave pump and let it spread. After about 30 minutes, turn everything back on. You can even automate this with a dosing pump loaded with a week’s worth of liquid coral food, though you’ll need to refrigerate the remaining supply and clean the container between refills.
Target feeding uses a pipette or turkey baster to deliver food directly onto individual coral polyps. It’s essential for LPS corals and NPS species with large polyps like sun corals. For target feeding, turn off all flow (return pump, skimmer, and wave pumps) and wait until the water is still. Mix your food with tank water to dilute it slightly, then gently release small amounts just above each coral. Set a timer so you don’t forget to turn your equipment back on.
Most reef tanks benefit from a combination of both methods. A daily broadcast feed covers your SPS and soft corals, while target feeding two to three times per week gives your LPS corals the meaty meals they need.
When Corals Are Most Receptive
Corals don’t feed passively at all times. Polyp expansion, which is when corals extend their tentacles to capture food, responds to specific environmental triggers. Research on suspension-feeding corals shows that polyps expand rapidly when they detect zooplankton in the water, sometimes reacting within seconds. The combination of water movement and food particles in the water column is what triggers the strongest feeding response.
Many coral species extend their polyps more fully after lights go out, making evening and nighttime the best window for feeding. If you notice your corals “fluffing up” and extending tentacles at a certain time, that’s your cue. Feeding during these windows means more food gets captured and less goes to waste, which also helps keep your water cleaner.
Managing Water Quality Around Feeding
Every bit of food you add to your tank is also a nutrient input. Uneaten food breaks down into nitrates and phosphates, and even food that corals do eat eventually returns nutrients to the water through waste. The key is matching your feeding volume to your tank’s ability to export those nutrients through protein skimming, water changes, and biological filtration.
If you’re keeping a mixed reef, aim for the nutrient range that suits your most sensitive corals. For a tank dominated by SPS, that means keeping nitrates between 1 and 5 ppm and phosphates between 0.01 and 0.05 ppm. For LPS-heavy or soft-coral tanks, you have more headroom. Test regularly when you first start a feeding routine, and adjust your skimmer run time or water change schedule based on what you see. Zero nitrates and zero phosphates are actually harmful to corals, starving their symbiotic algae of the nutrients needed to photosynthesize, so don’t chase the lowest possible numbers.