We all know about traditional soil gardens, the most common form of gardening. But soil has its drawbacks, and so many people turn to hydroponics, growing plants in water. Then there are mainland fisheries that use recirculating aquaculture systems that result in tank water that is polluted with fish effluent.
But what is aquaponics? Aquaponics is the cultivation of plants and aquatic animals in a soil-less, recirculating environment. Of course, fish live in water and plants need water to survive. But, unlike recirculating aquaculture systems, an aquaponics system is a recirculating ecosystem that converts ammonia-high fish waste to plant nutrition.
How does Aquaponics Work?
Aquaponics combines hydroponics, which is when you grow plants in water, with aquaculture that involves raising fish. Basically, you add a fish tank into your hydroponic growing system, resulting in a combined aquaculture hydroponic system.
Aquaponics eliminates the drawbacks of aquaculture and hydroponics and capitalizes on their benefits.
In commercial aquaponics, fish farmers raise fish for food. Typical types include trout, bass, tilapia, and perch, which are all large varieties.
If you want to experiment at home, you can keep goldfish in your tank instead. You won’t be producing fish for the table, but you will still be able to use the nutrient-rich water from your goldfish tank to irrigate your plants.
Components of Hydroponics Aquaponics
There are three main components in aquaponics. You need aquatic animals, fish being the specific requirement.
You need the nitrifying bacteria the fish produce. And you need the plants fish to require to ensure that the water will be clean again.
The plants need bacteria-rich water to grow. Then, as the plants grow, they remove nutrients from the water, which is how they clean it.
It’s a wonderfully organic cycle that results in an intensive and sustainable food production system.
Hydroponics can work well, but you have to add special nutrients to the water. In an aquaponics system, you simply feed your fish, which doesn’t cost much at all.
But the initial setup of an aquaponics system can be expensive.
What is the benefit of aquaponics?
Aquaponics provides us with a totally organic food production system. It relies on the constant recirculation of a water system that propagates an exchange of nutrients between plants and fish.
This results in a symbiotic relationship between the plants and fish in a controlled environment. Once the cycle is established, you won’t need any fertilizers, herbicides, or pesticides to support the growth of your plants.
Aquaponics is also a very water-efficient system. Estimates are that to grow plants aquaponics needs a sixth of the water to grow 8 times for food per acre than traditional agriculture methods use.
Because it doesn’t need soil, there aren’t any problems with soil-borne diseases and you won’t have to weed your garden. An aquaponics system is also easier to control in terms of production than systems that rely on sol control.
It is also an obvious solution to farming on non-arable land including deserts and sandy islands where the earth contains a lot of salt. It is also viable where the land is rocky.
There is a higher level of biosecurity, which lowers the risks posed by common contaminants. And, because it is a totally natural process that mimics nature, there is very little waste.
Ultimately, the benefit of aquaponics lies in food production in the form of protein from fish and vegetables. It has the potential to provide a way for landless and poor households to secure food and make a small income from surplus food production.
Disadvantages of Aquaponics
On the downside, aquaponics involves very high start-up costs when compared to traditional agriculture in soil and even hydroponics. It also requires farmers to learn about aquaponics how fish and bacteria work, and what growing vegetables involve.
This can, though, offer opportunities to non-governmental organizations (NGOs) to set up aquaponic farms and teach needy communities. They have great potential to meet the food security needs of people in developing countries.
Methods of Aquaponics
The four most common aquaponics systems used globally are deep water culture (DWC), media beds, nutrient film technique (NFT), and vertical aquaponics.
Deep Water Culture
DWC systems incorporate floating rafts in large water tanks. The plants are positioned in holes in the raft and the roots of the plant grow directly in the water.
This method is ideal for growing low-nutrient salad greens. It is commonly used by large-scale commercial farmers.
Media beds use various substrates in what is essentially an ebb and flow process. The media used provides mechanical filtration that removes solid waste, as well as biological filtration that converts ammonia to nitrates.
This method can be used to grow a wide range of crops from herbs and leafy greens to large fruiting plants. It can also be used on any scale and is ideal for hobby-scale and home systems.
Nutrient Film Technique
All the NFT requires is a thin layer of water. For instance, plants can be placed in holes drilled in PVC pipe that forms a narrow trough through which the nutrient-rich water flows.
These troughs can also be hung from a ceiling above other growing areas. Like DWC systems, the plant roots grow in the water.
NFT is used successfully to produce plants that don’t need support. This includes some herbs and even strawberries, which are often grown hydroponically both indoors and outdoors.
Vertical aquaponics enables farmers to grow a large volume of food in very small areas. One system involves stacking plants in a tower system.
The nutrient-rich water flows through the top of the tower and through a wicking material that allows the roots of the plants to absorb the water. The water then flows into a trough or back into the fish tank.
Vertical aquaponics is also suitable for growing plants that don’t need support.
Tips with Aquaponic Garden Set Up
If you are planning to set up an aquaponic garden, you will need the right equipment. The basics include grow-beds, a water pump, plumbing pipes and fittings, and possibly a sump pump.
You will need heating elements to ensure temperatures remain consistent. If your aquaponic garden doesn’t get adequate sunlight, you will also need to grow lights.
An active carbon filtration system or some other dechlorination device is another requirement. It’s also a good idea to get a backup generator in case of power outages.
Various organizations offer aquaponic training. If you are a total beginner, you should consider attending a few classes to maximize your return on investment.
What vegetables can you grow in aquaponics?
Many of our first-choice herbs and veggies thrive in aquaponic systems. They all have moderate nutritional needs and include leafy greens like lettuce, spinach, watercress, basil, other herbs, and okra.
Some vegetables with higher nutritional needs than these also do well in aquaponics systems. These include tomatoes, bell peppers, cucumbers, and strawberries.
Aquaculture hydroponic systems provide a sustainable way to provide good, nourishing food. While primarily used by commercial operations, they can be set up on a much smaller scale at home.
Why not give it a try?