Aquaponics Farming 101: The Game-Changing Way to Grow Fresh Food

BY DAKALO NEKHUMBE
Mar 31
4 min read

In an era where sustainability is a key focus across industries, agriculture is undergoing a transformation. One innovative solution gaining momentum is aquaponics farming—a closed-loop system that combines aquaculture (fish farming) with hydroponics (soil-less plant cultivation). By leveraging the natural symbiosis between fish and plants, aquaponics presents a revolutionary approach to food production that minimises waste, conserves water, and eliminates the need for synthetic fertilisers.

Let's explore what aquaponics farming is, what its benefits are and how much it would cost to start aquaponics farming:

How Does Aquaponics Work?

Aquaponics operates on a simple yet effective principle: fish waste serves as a nutrient source for plants, while plants filter and purify the water for the fish. In an aquaponics system, fish produce waste rich in ammonia, a natural byproduct of their metabolism. In high concentrations, ammonia becomes toxic to fish, necessitating its removal. This sets a symbiotic environment where beneficial bacteria convert toxic ammonia into nitrates, a nutrient plants readily absorb through their roots.

As plants utilise these nitrates, they effectively purify and filter the water, which is then recirculated back to the fish tank. This ensures that the fish continuously have a fresh supply of water while the plants have food. This closed-loop ecosystem fosters sustainable plant growth, supporting a diverse range of crops, including leafy greens, herbs, and fruiting vegetables.

What do you need to start an aquaponics system?

To establish a functional aquaponics system, the essential components begin with a fish tank, serving as the foundation of the ecosystem. A grow bed is where you would place your plants. This can be made with PVC pipes, floating rafts, or any food-grade container. A sturdy support structure is required to bear the weight of the grow bed. A bell siphon facilitates the flood-and-drain cycle necessary for media-based systems, while a water pump, sized according to the grow bed’s capacity, ensures proper circulation. To maintain oxygen levels, an aerator and air stones are used in both the fish tank and grow media beds. For a grow media you can use clay pebbles, expanded shale or gravel. And finally, you'll need timers and controllers to control the lighting, water flow and temperature, ensuring optimal conditions for both fish and plants.

What are the benefits of aquaponics farming?

Water conservation and reduced waste: Unlike traditional farming which requires large volumes of water, aquaponics allows water to recirculate between fish and plants in the grow bed making it a sustainable form of farming. Fish waste is used by the plants making it an environmentally friendly approach to farming.
Excellent for small spaces: This type of farming is ideal for big and small spaces alike. Aquaponics can be set up vertically making the most of a small space. Any environment can house an aquaponics system, from rooftops, to balconies and even basements.
Significant production of fish and plants: Aquaponics farming allows you to yield in twofold. You are raising fish while simultaneously growing edible plants. The symbiotic relationship between fish and plants allows plants to grow faster than they would in any setting because they are continuously absorbing fish waste.
Organically grown food: The closed environment of an aquaponics system minimises the use of pesticides. So, you grow organic food free from pesticides.

What plants and fish can you have in an aquaponics farm?

Fish:

Tilapia is a popular choice for beginners because of how quickly it grows and how easy it tolerates a number of water conditions. Tilapia is good for eating and serves as a good nutrient source for plants.
Goldfish is used only for aesthetic purposes. They are easy to care for and can survive in different ranges of water conditions. They are not for consumption.
Catfish can also survive in a number of water conditions, but are good for larger systems as they grow to be big. They are a good source of protein.
Trout is good for cooler climates, but are more challenging to raise as they require higher levels of oxygen and clean water.

Plants:

Lettuce, kale, spinach and Swiss chard are great choices for beginners because they grow quickly.
Basil, mint cilantro and parsley are good options for herbs to plant in your system.
Tomatoes, cucumbers, and peppers can be grown in aquaponics but really more care and attention.
Beans, peas, and radishes are also good plants to add to an aquaponics system.

Challenges to starting an aquaponics system:

The cost of beginning an aquaponics system depends on how big a system you would want. The costs can range from a few thousands to millions for bug commercial systems. An aquaponics system requires thorough understanding of how fish, bacteria and plants interact. Ensuring the thriving of each of these species is essential to the success of your system. You would need to regularly check the quality of your water to ensure that system is in balance. This includes checking the pH levels, ammonia, nitrates, nitrites, and dissolved oxygen. An understanding of how to maintain good water quality is necessary to help your plants grow and your fish to remain optimal.

Aquaponics farming is an interesting concept. It provides people with the smallest of spaces the opportunity to become farmers. Thorough research and knowledge of fish, plants, bacteria and water quality is essential to becoming a success in the aquaponics farming industry.