A Guide to the Best Fish Food in Aquaponics Systems

The significant difference between aquaponics system and other gardening methods is that it relies on the fish as the primary nutrient provider to the plants. Therefore, the fish feed must provide the nutritional requirements needed by the plants to grow. This is why many aquaponics growers are experimenting with various strategies to provide the best fish food for the fish and optimize its performance. This article discusses the best fish food in aquaponics systems.

What Do Fish in Aquaponics Systems Eat?

Different fish species require different diets. Some fish are herbivores, while others are carnivores and omnivores. Knowing the specific diet of your aquaponics fish is crucial to your system’s health and success. 

  • Herbivore: Herbivorous fish eat only plant matter. Meaning fish species with this diet require feed that is high in fiber. Tilapia is an example of an herbivore, and they feed on algae and other aquatic plants in the wild. Herbivorous fish may like fruits and vegetables, duckweed, and algae in an aquaponics system. 
  • Carnivore: Carnivorous fish such as trout and barramundi require rich in protein fish food, which usually consists of meat (live or dead). Most carnivorous fish are predatory and eat smaller fish species. Carnivorous fish can be given critters, live fish, or brine shrimp.
  • Omnivore: Omnivores are flexible eaters, meaning they can eat plants and meat. They are also easier to feed compared to other fish types.

The Basic Components and Nutrition of Aquaponics Fish Food

Proper fish nutrition and care in aquaponics are essential because the fish feed has to fulfill both the fish and plants’ nutritional needs. Without adequate nutrition, your fish will have slower growth, reduced breeding success, and low disease resistance.

Fish require a balanced diet and should regularly be fed healthy foods that meet their nutritional needs. Fish food must contain enough protein, carbohydrates, fat, fiber, phosphorus, and other vitamins and minerals for the fish to produce enough waste for the plants.

  • Protein: Protein is an essential component of building fish mass. Younger fish require a rich protein diet to grow at an optimal level during their grow-out stage. 
  • Fish Oil: Fish oil is a common component of fish feeds. Fish oil is high in two types of fats, omega-3, and omega-6, which are also beneficial for humans.
  • Carbohydrates: Carbohydrates are the most important and cheapest energy source for animals. Carbohydrates consist mainly of starch and sugar, which help bind the feed together to make a pellet. 
  • Lipids: Lipids provide energy and essential fatty acids for the fish’s growth and other biological functions. Fats also play a crucial role in absorbing fat-soluble vitamins and securing the production of hormones. Fatty acid deficiency in fish can cause reduced growth and limited reproductive efficiency.
  • Vitamins and minerals: These are necessary for fish health and growth. Vitamins are the organic molecules synthesized by plants that are important for the development and immune system functions. Minerals are required for the fish to synthesize their body components and cellular structures.

Types of Fish Food in Aquaponics Systems

There are several kinds of foods available for your aquaponic fish. You can use alternative fish food such as duckweed and leftover vegetables or feed your fish with commercial fish feed. The feed you provide will depend on the species, size, and age of the fish you are raising. Here are the common fish feeds used in aquaponics systems. 

1. Commercial Fish Food

Commercial fish foods are ready to feed and formulated to meet your fish’s dietary requirements. You can go for products that do not include GMO ingredients in purchasing commercial fish food, especially if you plan to eat your fish. Keep in mind also to buy high-quality fish food that offers balanced nutrition. 

Most commercial fish feeds are in the form of pellets or flakes. Pellets are fish feed that sinks in the water while flakes float. The advantage of using fish pellets is that they can swallow them naturally as they sink into the water. The disadvantage of pellets is they need to be taken out of the water after feeding to avoid water quality issues. 

The advantage of using fish flakes is that they do not quickly get spoiled and stay on top of the water. Your fish behavior will determine the selection between pellets and flakes. 

2. Homemade Fish Food

Homemade fish foods are ideal for small aquaponics systems. Making your own fish food will ensure you have total control over what your fish eats and what goes into your system. If you decide to make your fish food, ensure you give the right balance of nutrients required for fish growth. Some homemade fish food is duckweed, worms, insects, vegetables, and other aquatic plants.

Determining How Much Fish Food to Feed Your Aquaponics Fish

Most aquaponics growers follow the simple rule of feeding their fish what they can consume in just five minutes and removing any uneaten fish after five minutes to avoid unwanted water quality issues. However, if you have a new system and are still cycling with the fish process, feeding should be kept in small amounts until the system is fully cycled. 

Also, keep in mind that fish generally consume 1% to 2% of their body weight daily. You can feed your fish two or three times a day. You can feed your fish manually or use an automatic fish feeder if you are not in your garden 24/7. You can schedule your feeding time in the morning, afternoon, and before dusk.

If you plan on a twice-a-day feeding, you can schedule it in the morning and afternoon. Make it a part of your feeding habit to observe your fish while feeding to see if there are changes in their behavior. If you notice something is not normal, immediately give the proper attention to avoid more issues.


Feeding your fish with high-quality food benefits the fish and the plants, especially if you harvest fish for consumption. Therefore it is essential to feed your fish with the best fish food suitable for their species. Commercial fish food is one of the easiest ways to feed your fish. However, it can also be expensive. So if you want to cut costs on your fish food, you can feed your fish with homemade fish food. Make sure that the homemade fish food meets the nutritional requirements required by the fish and plants for healthy growth.