Alternative Fish Food in Aquaponics

As the popularity of aquaponics continues to grow, the significance of fish food becomes a focal point in maintaining the delicate balance between this ecosystem's aquatic and plant components. Commercial fish foods, while effective, present challenges in terms of environmental impact, cost, and nutritional content. In this blog, we will explore alternative fish foods for aquaponics and explore options that address these challenges to contribute to aquaponic systems' overall sustainability and efficiency. 

The widely used traditional commercial aquaponics fish food comes with environmental, economic, and nutritional challenges. As the demand for sustainable agricultural practices grows, there is a need to explore alternative fish food options that address these issues without affecting the efficiency and productivity of aquaponics systems. This blog discusses alternative fish food for aquaponics and examines the benefits and challenges that are reshaping the landscape of aquaponics. 

The Importance of Fish Food in Aquaponic Systems

Fish food plays an important role in aquaponics, as the health and well-being of the fish directly impact the quality of nutrients introduced into the system. This is why understanding the importance of alternative for fish food is essential for optimizing the symbiotic relationship between aquatic and plant components.

Traditional Fish Food and its Limitations:

While commercial fish foods are essential in aquaponics, they come with limitations, such as:

1. Environmental Impact: Using commercial fish foods contributes significantly to environmental degradation, primarily through the reliance on fishmeal derived from wild-caught fish stocks. Overfishing to produce fishmeal disrupts marine ecosystems, impacting the delicate balance of aquatic life. This practice depletes the populations of essential fish species and disrupts them by relying on the food chain, affecting marine biodiversity. 
2. Cost Considerations: Fishmeal-based feeds contribute to the overall expenses of maintaining an aquaponics system.
3. Nutritional Imbalance: Commercial fish foods may not be enough for the dietary requirements of both the fish and the plants in the aquaponics system. Nutrient imbalance can lead to deficiencies or excesses in essential nutrients that can affect the health and growth of fish and plants.

 

What Does 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. 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). 
• Omnivores: Omnivores are flexible eaters, meaning they can eat plants and meat. They are also easier to feed compared to other fish types

Alternative Fish Food for Aquaponics

A.Insects and Larvae

1.Black Soldier Fly Larvae

 

Black Soldier Fly larvae have become an excellent alternative organic fish food in aquaponics systems. These larvae, scientifically known as Hermetia illucens, exhibit several properties that make them a valuable nutritional resource.

• Black soldier fly larvae are highly efficient at converting organic waste into protein.
• Black soldier fly larvae are nutritionally dense, containing a substantial amount of protein, fats, and calcium.
  
• Black soldier fly larvae have a rapid growth rate, reaching maturity quickly. This characteristic makes them a readily available and sustainable source of fish feed.

Nutritional Value:

• Protein: Black soldier fly larvae are rich in protein, with levels often exceeding those found in traditional fish meal.
• Fats: They contain beneficial fats, contributing to the overall energy content of the larvae.
• Calcium: Black soldier fly larvae are an excellent source of calcium, promoting bone health in fish.

2.Mealworms

 

Mealworms, the larvae of darkling beetles (Tenebrio molitor), have gained popularity as organic fish food in aquaponics systems. These insects possess unique properties that make them an attractive nutritional source for fish.

• Mealworms are rich in protein, making them a valuable supplement for promoting fish growth and health.
• Mealworms are versatile and can consume various organic materials, including kitchen scraps, grains, and vegetables.

Nutritional Value:

• Protein: Mealworms provide substantial protein, often comparable to or exceeding traditional fish meal.
• Fats:They contain beneficial fats, including essential fatty acids crucial for fish development.
• Fiber: Mealworms also offer some dietary fiber, promoting digestive health in fish.
• Micronutrients: They contain essential micronutrients, such as vitamins and minerals, contributing to overall fish well-being.

3. Earthworms

 

• Earthworms are a good source of protein, an essential component for fish growth and vitality.

• While not as high in fat as some other alternatives, earthworms provide a moderate amount of fats, contributing to the energy content of the feed.
• Earthworm castings (vermicompost) are nutrient-rich organic material that benefits plants in aquaponics systems. The presence of earthworms can improve nutrient cycling and soil structure.

Nutritional Value:

• Protein: Earthworms contain a decent amount of protein, making them a suitable supplement for fish in aquaponics.
• Fats: While not particularly fatty, earthworms provide essential fats for fish health.
• Micronutrients: Earthworms are a source of various vitamins and minerals, contributing to the overall nutritional diversity of the fish diet.

B.Plant-Based Feeds

1.Spirulina 

 

Nutritional Value:

• Protein: Spirulina is a potent source of high-quality protein, containing all essential amino acids needed for fish growth.
• Vitamins: It is rich in vitamins such as B-complex, particularly B12, which is vital for fish health.
• Minerals: Spirulina provides essential minerals like iron, calcium, and magnesium.
• Antioxidants: The presence of antioxidants contributes to fish immunity and overall well-being.

2. Duckweed

Duckweed belongs to the Lemnaceae family and consists of tiny, rounded leaves that create a dense mat on the water's surface. This small floating aquatic plant is gaining popularity as an alternative organic fish food in aquaponics systems. Its rapid growth and ability to cover the water surface make it a highly efficient and productive choice for sustainable fish nutrition.

Nutritional Value: Its nutritional profile includes:

• Protein: Duckweed is rich in protein, often containing levels comparable to or higher than conventional protein sources used in commercial fish feeds.
• Amino Acids: It provides a range of essential amino acids crucial for fish growth and overall health.
• Vitamins and Minerals: Duckweed is a source of vitamins such as A, B, and C, as well as minerals like calcium and phosphorus..

How to Make Organic Fish Feed for Aquaponics

Below are the three options on making your own fish food.

1.DIY Vegetarian Fish Food

Make this vegetarian fish food for your herbivore's aquaponics fish. They will love it!

Ingredients:

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

Procedure:

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. Add hot water, and mix the gelatine in a bowl.
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. 

Ingredients:

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

Procedure:

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. Add hot water, and mix the gelatine in a bowl.
5. Mix the pureed vegetables and gelatine well and store them 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.

Ingredients:

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

Procedure:

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

Benefits of Alternative Fish Food

Below are the benefits of using alternative fish food in your aquaponics systems.

A.Environmental Sustainability:

• Reduces reliance on traditional fish feeds that may contribute to over fishing and environmental degradation.
• Promotes cultivating alternative fish foods, like insects and plants, contributing to a more sustainable and eco-friendly aquaponic system.

1. Cost-Effectiveness:

• Low production costs compared to commercial fish feeds, especially when utilizing alternatives like insect larvae or homegrown plant-based options.
• It minimizes the financial burden on aquaponics practitioners, making the system more economically viable.

2. Customization of Nutrient Content:

• Allows for precise control over the nutrient composition of fish diets, catering to the specific nutritional needs of different fish species and growth stages.
• Enables adaptation to changing requirements within the aquaponic system, optimizing overall fish health and growth.

3. Reduced Dependency on Commercial Feeds:

• Enhances the self-sufficiency of aquaponic systems by reducing reliance on external, commercially produced fish feeds.
• Mitigates risks associated with market fluctuations, supply chain disruptions, and price volatility in the commercial feed industry.

4. Promotion of Circular Economy:

• Utilizes waste streams within the aquaponic system, such as organic waste and excess plant material, to produce alternative fish foods.
• Creates a closed-loop system where by-products and waste contribute positively to the overall health and productivity of the aquaponic environment.

5. Diversification of Feed Sources:

• Introduces a variety of feed sources, such as insect larvae, mealworms, duckweed, and azolla, reducing the monotony of fish diets.
• Enhances the nutritional diversity available to fish, potentially improving their overall well-being.

6. Optimized Resource Utilization:

• Maximizes the efficient conversion of resources within the aquaponic system by utilizing alternative fish foods that can thrive on locally available inputs.
• Reduces the environmental impact associated with resource-intensive conventional fish feeds.

7. Supports Sustainable Agriculture:

• Aligns with principles of sustainable agriculture by minimizing the ecological footprint of aquaponic systems.
• Encourages responsible and ethical practices in aquaculture, promoting a holistic approach to food production.

Conclusion

In conclusion, adopting alternative fish food in aquaponics brings multifaceted benefits, ranging from environmental sustainability and cost-effectiveness to improved nutrient diversity for fish health. Aquaponics practitioners are vital in promoting ecologically responsible and economically viable aquaculture practices by reducing reliance on traditional fish meals. These benefits contribute to developing resilient, efficient, and environmentally conscious aquaponic systems.