Feeding Your Saltwater Aquarium: Best Practices for Fish, Invertebrates, and Corals

Once you've set up your saltwater aquarium and filled it with the essentials, it's time to start thinking about feeding what's inside it. You want to research the nutritional needs of the specific species of fish, invertebrates, and corals inside your tank so you know how to meet their needs. Keep reading to learn more about best practices on how to feed your fish, invertebrates, and corals to help ensure you maintain a healthy aquarium.

Best Practices for Feeding Saltwater Fish

Learning how to feed your fish properly can take time. You want to research what food is best for each species, figure out timing, and then use proper feeding practices to ensure your fish consume enough. But with time and tinkering, you can keep your fish healthy.

Consider their needs

Be sure you're meeting your fish's individual nutritional needs. For instance, some fish need multiple feedings every day. Others only need one meal a day. Consider their diet (carnivore, omnivore, herbivore), and choose food accordingly. For example, firefish are carnivores and need a mostly meat-based diet.

Be mindful of the types of food you give your fish

Feeding your fish a variety is important to help ensure they receive as many nutrients as possible. What you feed your fish can depend on preferences too. Some fish need food that floats, so flakes are a good choice. Others, like yellow watchmen goby, are primarily bottom feeders and need food that sinks, like pellets.

Feeding schedule

Not all fish eat on the same schedule. Fish compete for resources in the wild and will in the aquarium too. You want to ensure all your fish have enough to eat. You can feed them slowly instead of dumping the food in all at once to give everyone access to food.

If you have a mix of aggressive and shy fish, you can use a feeding stick or a turkey baster to place the food closer to the more passive feeders, preventing the aggressive feeders from stealing it. Placing food in the same locations every time is also a good idea. It gives bottom feeders a chance to consume the food the fish at the top of the tank might miss.

Don't over or underfeed

The general rule when it comes to feeding fish is that you want to give what can be consumed in five minutes. Fish tend to eat small amounts throughout the day, so feeding them on a schedule can be very helpful.

You've likely overfed your fish if any pelleted or flaked food is left over.

Leftover food can lessen water quality. Remove any food from the tank that isn't consumed after one to two hours. Otherwise, it can lead to problems for the water and your fish, including low oxygen or pH levels or high levels of ammonia or nitrates.

To ensure you don't overfeed your fish, provide them with small portions throughout the day. And this is easier if you're at home for most of the day. If you're gone during the day, aim to feed them once in the morning and again in the evening. You can also use a timed feeder if your fish need to be fed more than twice a day.

Underfeeding can be harder to spot, so you need to pay attention to your fish. If your fish have a sunken belly and seem lethargic, it might be a sign they're malnourished. One sign that you might need to feed your fish more is if they consume all the food in less than 5 minutes. If this happens, feed them a little more each time until you find the right mix.

Variety is the spice of life, even for your saltwater fish

Just like it's a good idea to get variety in your diet, it's important your fish get the same thing. Fish should be fed a wide range of foods, including flakes, pellets, and fresh or live food. Some examples of food you can feed saltwater fish include krill, brine shrimp, phytoplankton, plankton, and seaweed. Fish also enjoy the occasional treat. The Aqueon Stick'ems Freeze-Dried High Protein Treat provides nutrient-packed freeze-dried brine and Mysis shrimp, plus spirulina seaweed for color.

Best Practices for Feeding Invertebrates

Invertebrates or animals with no backbone, like mollusks (snails) or crustaceans like crayfish or shrimp, can also be added to a saltwater aquarium. Invertebrates can help keep the tank clean. They can also contribute to algae control and clean up non-living material.

Saltwater invertebrates fall into two categories: sessile invertebrates, inverts attached to a substrate and do not move (corals, feather duster worms, and anemones) and motile invertebrates, inverts that can move around (shrimp, crabs, and sea stars). We'll discuss corals in the next section.

How invertebrates usually get their food

Depending on the species, invertebrates get their food in various ways. Some, like mollusks, have a radula or tiny teeth they can use to consume food. Others filter food through the water. Some even consume leftover fish food, coral, or other plants — helping keep the water clean.

Invert food

Feed your motile inverts in a way similar to how you feed your fish. These inverts, often omnivores or carnivores, will eat sinking pellets and freeze-dried or frozen meaty foods. It's important to research the diets of each invert species you choose for your tank to know how to feed them.

Target feeding

Target feeding, aka direct feeding, is just what it sounds like. Take a pipette or dropper of liquid food and squeeze it directly toward the invertebrate. Be sure to follow the food's recommendations on target feeding your inverts. Overfeeding is easy to do and can affect water quality.

Best Practices for Feeding Corals

Corals, part of the sessile invertebrate group, have individual nutritional requirements depending on the species. No matter what coral you choose, investigate what the coral needs to be healthy. Sessile inverts filter their food from the water and require liquid foods, phytoplankton, or small zooplankton, like rotifers or copepods.

Most corals are filter feeders that feed on phytoplankton and zooplankton. They'll often extend their polyps at night to capture food. Some larger polyped coral, like Elegance coral, Bubble coral, and anemones, can be fed larger food like krill or shrimp. To help make feeding time easier, turn your tank's current off entirely or low during mealtime.

Photosynthesis

Photosynthesis is the scientific process where plants utilize sunlight to convert carbon dioxide and water into glucose and oxygen. The algae, specifically zooxanthellae, live inside the coral's tissue. The algae converts light to energy. It produces sugars, which are then released into the coral's body and absorbed by the coral. This is how the algae that live within the coral's body make their own food. To help your corals thrive, be sure you choose the right lighting for your reef tank.

Direct feeding

Direct feeding, aka target feeding, is when you use a syringe or dropper to place the food near the coral's mouth. Target-feeding coral involves taking a dropper and putting food directly on the coral. Place the food on or near the mouth. Target feeding can be more effective than indirect feeding as it can help ensure the food is consumed.

Indirect feeding

Indirect feeding, or broadcast feeding, is when you let the corals feast on the food in the water. As its name implies, broadcast feeding involves dispersing the food in the water so it spreads out in the tank. Simply place the food in the tank and let the corals consume it.

The Importance of Properly Feeding Your Saltwater Fish, Coral, and Invertebrates

Providing good nutrition and other supplements for your saltwater fish, corals, and invertebrates is part of maintaining a healthy saltwater aquarium. It just takes some time and practice to dial in what each species in your aquatic environment needs.

Learn more about caring for your marine invertebrates in The Ultimate Guide for Marine Invertebrates for Nano Tanks, and learn how to avoid common mistakes in saltwater aquarium keeping with Common Issues in Saltwater Aquariums and How to Fix Them.