Alternative Fish Food in Aquaponics

Fish food is one of the most expensive inputs for small- scale aquaponics systems. Fish food provides most of the nutrients the fish and plants require to thrive. The healthier the fish, the more efficient they are in producing fish waste that are converted into ‌nutrients for the plants. 

Commercial fish food can be bought anywhere, but knowing the alternative fish food for your aquaponics fish is essential if you want to save on your aquaponic system or in case commercial pelleted feed is unavailable. This article discusses the alternative fish food in aquaponics systems and how to produce them at home.


Fish Food In Aquaponics

What do Aquaponics Fish 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. Tilapia is an example of an herbivore; they feed on algae and other aquatic plants in the wild. Herbivorous fish may like fruits, vegetables, and aquatic plants like duckweed and algae.
  • Carnivore: Carnivorous fish such as trout and barramundi require rich in protein fish food, which usually consists of meat (live or dead). Carnivorous fish can be given critters, live fish, or brine shrimp. Most carnivorous fish are predatory and eat smaller fish species.
  • Omnivore: Omnivores are flexible eaters, meaning they can eat plants and meat. They are also easier to feed compared to other fish types.

What Should You Feed Your Aquaponics Fish

When feeding your fish, you need to determine if your fish is carnivorous, omnivorous, or herbivorous. You have the option of providing your aquaponics fish with commercial fish food or alternative fish food. Commercial fish food is packed with nutrients that will help your fish stay healthy while feeding your fish with alternative homemade organic food will ensure that your system and the plants in your system are organic.

Alternative fish food is ideal if you have a small aquaponic system. This way, you can be sure what your fish is eating and what your plants are receiving. Also, if you plan to eat your fish, you know what goes into the food your fish is eating.  

Benefits of Alternative Fish Food in Aquaponics

If you choose to feed your aquaponics fish with alternative food, ensure you give the right amount of nutrients needed for fish growth. Here are the benefits of feeding your aquaponics fish with an alternative or homemade fish feed.

  • Using alternative or homemade fish food saves money as most of the food you usually throw away can be eaten by the fish.
  • You have control over what your fish eats. 
  • Alternative fish food or homemade fish food has all the nutrients your fish need.

Alternative Fish Food in Aquaponics

These are the alternative fish feed in aquaponics.

1. DIY Vegetarian Fish Food

Make this vegetarian fish food for your herbivores aquaponics fish. They will love it!


  • Cucumber - 136g
  • Spinach - 136g
  • Frozen peas- 136g
  • Oats - 136g
  • Gelatin (unflavored) - 136g


  1. Blanch all the vegetables and let them cool.
  2. Blend all the vegetables to form a puree.
  3. Add the oats and blend again. Set aside.
  4. Take the gelatine in a bowl and add hot water and mix well.
  5. Add the gelatine to the vegetable puree and store it in ice cube trays. 

2. DIY Meat Fish Food

This DIY protein-rich meat fish food is for carnivorous aquaponics fish. 


  • Shrimp - 136g
  • Whitefish - 136g
  • Vegetables such as carrots, broccoli, cauliflower, etc. - 136g
  • Gelatin (unflavored) - 268g


  1. Cut the vegetables and boil them.
  2. After boiling, let them cool and blend the vegetables to form a puree.
  3. Blend the shrimp and fish.
  4. Take the gelatine in a bowl and add hot water and mix well.
  5. Mix the pureed vegetables and gelatine, mix well and store in ice cube trays.
  6. Use when needed.

3. DIY Standard Fish Food

This is the most common DIY fish food you can feed your fish.


  • Garlic - 68g
  • Vegetables (spinach, broccoli, cauliflower, and other veggies) - 408g
  • Gelatin mix (unflavored) -268g
  • Water - 1cup
  • Seafood - 68g
  • Fish vitamins -1 drop


  • Cut the vegetables and boil them. Let them cool.
  • Blend the vegetables with the seafood and garlic. 
  • Add one drop of fish vitamins.
  • Take the gelatine in a bowl and add hot water and mix well.
  • Mix the pureed vegetables and gelatine, mix well and store in ice cube trays.

Storing your homemade fish food: Once your homemade fish foods are frozen, remove them from the ice cube tray and transfer them to an airtight container. You can use them when needed. If stored properly, the frozen fish can last for a year. 

 4. Duckweed 

Duckweed is a fast-growing, floating, small aquatic plant that grows well in the nutrient-rich water in your aquaponics system. Duckweed is rich in protein, is highly fast-growing, and can double itself in just a few days.

 These fast-growing plants help create a healthy environment for the fish by utilizing excess nutrients in the fish tank, such as nitrogen and phosphorus. However, duckweed should be grown in a separate tank because they grow fast in undisturbed and slightly shaded water. Duckweed makes an excellent alternative fish feed for tilapia, koi, perch, and trout.


Duckweed As Fish Food In Aquaponics


5. Azolla

Azolla is a water fern that grows floating on the water's surface. Azolla fixes the atmospheric nitrogen and essentially creates proteins from the air. Azolla is also rich in protein and is produced in some aquaponics systems as an alternative fish feed. This aquatic plant should be grown in a separate fish tank that is slightly shaded with slow water flow.


Azolla As Fish Food In Aquaponics


6. Insect and Worms

Insects and worms can be included as alternative fish feed in aquaponics because, for centuries, they have been a natural source of food for fish and many other animals. Insects are a healthy nutrient source in aquaponics because they are rich in protein and lipids, and are full of essential minerals. 

Insects are also rich in amino acids, often lacking in many commercial fish foods. Carnivorous fish can be fed by crickets, insect larvae, flies, tiny crustaceans, cockroaches, fish eggs, and many worms, like black worms, earthworms, and red wigglers.


Worms in Aquaponics Systems


7. Black Soldier Flies

The larvae of black soldier flies are very high in protein and are considered an essential source of protein for livestock, including fish. The life cycle of this insect makes it an attractive addition to some farming systems in favorable climate conditions.

In culturing black soldier flies, the food waste or manure is placed in a compost unit with enough drainage and airflow. The larvae are then placed, and when they reach maturity, they are collected and processed into fish feeds.

 The adult black soldier flies are neither a vector for diseases nor attracted to human activities. Adult flies simply mate and then return to the compost unit to lay eggs and die after a week. 

One advantage of using black soldier flies is that they have been shown to prevent houseflies and blowflies in their facilities and help decrease the pathogen load in the compost. However, before feeding the larvae to the fish, the larvae should be processed safely by baking in the oven (170°C for 1 hour) to destroy any pathogens, and the resulting dried larvae can be ground processed as fish feed.


Black Soldier Fly As Fish Food In Aquaponics


8. Moringa

Moringa oleifera is a species of a tropical tree that is very high in nutrients, protein, and vitamins. The moringa is a valuable homemade alternative fish feed for aquaponics. 

Moringa is a fast-growing tropical tree and drought-resistant. It can be propagated easily through cuttings or seeds, but they are intolerant of frost and cannot survive in colder climates. All parts of the tree are edible for human consumption, but for aquaculture, the leaves are used to feed the fish. For leaf production, the leaves are harvested and can be fed to the fish fresh or dried.


Moringa As Fish Food In Aquaponics


9. Other Fish Food Alternatives

You can feed your plant-feeder fish with vegetables that can be grown easily in your aquaponics grow beds, such as kale, lettuce, watercress, and fruits like bananas, apples, and grapes.


Fruits And Vegetables As Fish Food In Aquaponics


Here is a list of common aquaponics fish that you may be growing and what they prefer to eat in their natural habitat. 

1. Trout: Carnivorous

  • Smaller fish 
  • Aquatic insects such as water fleas, mayflies, etc.
  • Crustaceans
  • Worms
  • Salmon eggs

2. Largemouth Bass: Carnivorous

  • Smaller fish
  • Insects
  • Crayfish
  • Frogs
  • Small aquatic birds

3. Bluegills And Crappies: Carnivorous

  • Small fry fish
  • Aquatic insects
  • Crustaceans
  • Zooplankton

4. Koi: Omnivorous

  • Small Insects
  • Fruits - apple, watermelon, grapes
  • Vegetables - lettuce, broccoli
  • Meats - shrimp, bugs, crayfish, worm

5. Goldfish: Omnivorous

  • Vegetables
  • Insects
  • Worms
  • Small crustaceans

6. Catfish: Omnivorous

  • Water plants
  • Algae
  • Insects
  • Beetles
  • Small fish
  • Dragonflies
  • Crawfish

7. Tilapia: Omnivorous

  • Vegetables
  • Algae
  • Duckweed

Feeding your aquaponics fish with alternative fish feed can help lower the costs of maintaining your system and ensure that your fish and plants are organic. However, if these fish food alternatives are unavailable at your location, the commercial fish food also works well. Both work well, and the choice is yours for how you want your aquaponics system to be. Thank you for taking the time to read this article. Feel free to leave your comment below.



2 Responses



January 22, 2023

Once the food is in ice cube form will the fish just eat the ice cube? Thanks.

timothy seeley

timothy seeley

July 27, 2021

my squash and cucumbers doesnt get vegtables on them unless i give them fertilizer than they do not always produce right any advice will help

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