Introduction to Aquaponics

September 26, 2021

Today, many people have turned to aquaponics farming to grow food because of its sustainability and organic way of producing food. Aquaponics has grown and developed by aquaponics growers for commercial purposes and backyard gardening to sustain the high demand for organic food by the growing population in urban areas. This introduction to aquaponics covers everything about aquaponics to serve as your guide in learning aquaponics.

What is Aquaponics?

Aquaponics is a combination of aquaculture (the growing of fish and other aquatic animals) and hydroponics (the growing of plants without soil in a recirculating environment).

How Does Aquaponics Work?

In aquaponics, the plants are grown in the grow bed, and fish are placed in the fish tank. The water from the fish tank that contains fish waste is fed to the grow bed, where billions of naturally occurring beneficial bacteria break the ammonia down into nitrites and then into nitrates. Plants absorb these nitrates and other nutrients to help them grow. In return, the plants clean and filter the water into the system. The fresh, clean, and oxygenated water then recirculates back to the fish tank, where the cycle will begin again.

The Nitrogen Cycle

As you have noticed, besides the plants and fish, there is a third component that plays a crucial role in aquaponics. These are the beneficial bacteria, which make the nitrogen cycle in an aquaponics system possible.

The nitrification process is an important biological process in aquaponics. Nitrogen (N) is a chemical element that is an essential building block for all life forms.

The nitrification process is a key aspect for a successful aquaponics system because:

Nitrification provides nutrients to the plants and eliminates ammonia and nitrite, which are toxic to the fish.
The nitrifying bacteria that live on land also will establish naturally in the water or on any wet surface, converting the ammonia from fish waste into nitrate for plant use.
Plants need nitrogen to grow, and they need nitrate to perform their growth processes as they easily assimilate to their roots and user- friendly to all types of plants.

A Brief History of Aquaponics

The idea of using fish waste to fertilize plants has existed since early civilization in both Asia and South America. The pioneering works of the New Alchemy Institute and some North American and European academic institutions in the late 1970s and the further research in the following decades helped develop the basic form of aquaponics into the modern food production system.

The 1980s and 1990s saw advances in aquaponics system designs, biofiltration, and the identification of the optimal fish-to-plant ratio. These advances led to developing a closed system that allows the recycling of water and nutrient build-up to plant growth. Although used since the 1980s, aquaponics is still considered a new method of food production, with only a few researchers and practitioners worldwide.

James Rakocy of the University of the Virgin Islands (USA) was the industry leader regarding research and development. He developed vital ratios and calculations that maximize the production of both fish and vegetables while maintaining a balanced ecosystem.

Other researchers from different countries, such as Wilson Lennard of Australia, Nick Savidor of Canada, and others, have contributed to the development of aquaponics. Their research breakthroughs have paved the way for various practitioners and companies to sprout worldwide.

Advantages of Aquaponics

1. Efficient Use of Water

One of the significant benefits of aquaponic growing is the minimal water wasted compared to conventional farming. Although the name implies "water," aquaponics uses approximately 90% less water than traditional agriculture. The water is rarely changed or discarded since it's recycled repeatedly through the entire system. The water is lost only through natural evaporation.

2. Health Benefits

The number one reason most people resort to raising their own produce is that they want to eat healthier. Aquaponics do not use chemicals or fertilizers to grow plants, so you can be confident that your plants are organic because you know what went into growing them. Knowing that your product is healthy for you and your family will give you great personal satisfaction.

3. Environmental Benefits

Besides the efficient use of water, aquaponics offers environmental benefits. Aquaponics does not need large areas of agricultural land, so the negative impacts on soil are avoided, and it doesn't need land conversion. Another thing is there is no pesticide and other chemicals used which would pollute the land and water ecosystems.

4. Year-round Gardening

Aquaponics allows growers to grow food all year round by regulating the temperatures as per what you are growing and by using greenhouses.

5. Two-Source of Income

Aquaponics offers two streams of income, both fish and vegetables.

6. Food Security

Food security and food independence are increasingly becoming important. Aquaponics is another means of living a more self-sufficient lifestyle.

Disadvantages of Aquaponics

1. While small-scale aquaponics systems can be experimented with and built with a small amount of money, a large-scale commercial aquaponics systems can be costly.

2. Aquaponics uses lots of power, especially if you're maintaining your production during the winter. Water pumps, heating, and lighting consume lots of power. Power can be minimized by using alternative power sources as wind or solar systems. However, installing this alternative power source can be costly.

3. Water quality requires frequent monitoring and testing, so you have to regularly check the water and all the mechanical parts of the system.

4. The food produced from aquaponics farms is still limited to niche and exclusive markets.

5. Balancing an aquaponics system can be tricky.

Aquaponics vs. Hydroponics

The presence of fish in aquaponics is the most significant difference between aquaponics and hydroponics. But there are still some significant differences between the two systems, these are:

Difference Between Aquaponics and Hydroponics

	Hydroponics	Aquaponics
Definition	The growing of plants without soil using a nutrient solution.	The growing of plants and fish without soil using fish waste as a natural fertilizer for the plants.
Nutrient Used	Chemical Nutrients	The nitrifying bacteria convert fish waste into nitrates.
Costs	Less cost-effective because of the increasing scarcity of chemical nutrients.	Very cost-effective since organic matter is used to supply nutrients.
Startup Costs	Lower start up cost.	Have higher startup costs because of the additional components like fish tanks, water pumps, power, heater, etc.
Startup Speed	Fast to start up.	Slower to start up because new systems require cycling, which can take several days.

Temperatures	The temperature needs to be lower to prevent bacterial growth.	Requires a higher temperature to encourage bacterial growth.
Productivity	Produce lower yields compared to aquaponics.	Higher yields because of its ability to produce two sources of produce from fish and plants.
Maintenance	Requires higher maintenance as the water needs to be replaced regularly because of salt build-up, which is toxic to the plants.	Aquaponics is easy to maintain because the water does not need to be replaced because it is a recirculating system. .

Similarities Between Hydroponics and Aquaponics

The similarities between hydroponics and aquaponics are:

Both growing methods grow plants without the use of soil.
Both aquaponics and hydroponics systems use nutrient-rich water to grow plants.
Both growing methods can produce higher yields than the traditional growing methods.
Plants grown in hydroponics and aquaponics grow faster than other growing methods.
Both can practice year-round gardening if built indoors or in a greenhouse.
No weeding is involved in both systems, as there is no soil involved.

The Different Methods of Aquaponics?

The three different methods of aquaponics are:

1. Media Bed Aquaponics System

Also called Flood and Drain, the media bed is common for small-scale aquaponics systems and popular with do-it-yourselves aquaponics home growers. The media bed system design is simple and efficient with space and has a low initial cost suitable for beginners in aquaponics.

The media bed consists of a grow bed filled with grow media (expanded clay pebbles, gravel, lava rock) into which the vegetables are planted. The water from the fish tank is pumped or flows by gravity into the grow beds so that the plants can access the nutrients. The grow beds host the colony of nitrifying bacteria and provide a place for the plants to grow. Some media bed aquaponics systems are run by flooding and draining the grow beds, using a bell siphon to drain the water when it reaches a saturation point.

2. Nutrient Film Technique

The Nutrient Film Technique (NFT) is a hydroponic growing technique adapted to aquaponics because of its simple yet effective design that works well in some environments. This method uses horizontal pipes (PVC) with shallow streams of nutrient-rich water flowing through them. The NFT is popular for commercial aquaponics and is useful in urban places where space and food production are problems.

3. Raft System

Also known as the Deep Water Culture (DWC), the raft system of aquaponics is one of the most efficient aquaponics system designs. This system is often used in large-scale or commercial aquaponics systems because of its mass production capability.

In a raft system, the nutrient-rich water circulates through the long canals, usually at a depth of about 20 cm, while rafts (polystyrene or foam board) float on top. The plants are grown on the raft boards that are supported within holes by net pots. Plant roots hang down in the nutrient-rich, oxygenated water, where they absorb oxygen and nutrients to grow rapidly. The nutrient-filled water flows continuously from the fish tank through the filtration process, then to the raft tank where the plants are grown, and finally back to the fish tank. Most often, the raft tank is separate from the fish tank.

What Types of Fish Can You Use in Aquaponics?

Fish play an essential role in an aquaponics system because their waste acts as a natural fertilizer for the plants. To achieve a maximum growth output from your fish, you must know the best fish to raise in aquaponics. To have maximum growth output from your fish, choose the best fish for your system that is disease resistant, easy to grow, and readily available in your location. The most common fish species used in aquaponics are listed below.

Edible Fish:

Tilapia
Carp
Trout
Catfish
Largemouth Bass
Salmon

Ornamental Fish:

Goldfish
Koi

Invertebrates

Other aquatic invertebrates, such as prawns, can also be used in aquaponics. Prawns can be a great addition to an aquaponics system because they consume the excess fish food, fish waste, and other organic waste in the tank, which helps support a healthy system.

What Types of Plants Can You Grow in Aquaponics?

Almost all plants can be grown in an aquaponics system. Plants help maintain the aquaponics system's overall cycle by cleaning and oxygenating the water. Plants also absorb the nitrates in the water, thus cleaning it before recirculating back to the fish.

Choosing the best plant to grow in your aquaponics system is important for your system's overall success. If you have a new system, avoid planting nutrient-hungry plants like tomatoes and stick to easy-to-grow plants like leafy greens, lettuces, and herbs. Nutrient-hungry plants require many nutrients, so wait until the fish in the system is larger before you can start adding tomatoes, peppers, and other fruit-bearing plants.

In Aquaponics, plants are grown in the grow bed, pipes, or floating rafts. If you're using grow beds, make sure that the grow bed container is strong and deep enough to hold the grow media and growigplants when they grow. If you're planting in a floating foam, make sure that it is lightweight and buoyant and can hold the plants upright. In planting your plants, make sure that the base that holds the plants is sturdy enough to keep the plants when they grow up.

Best Plants for Small Aquaponics Systems:

Lettuce
Basil
Watercress
Kale
Spinach
Swiss chard
Arugula
Chives
Pak choi
Wheatgrass
Radish sprouts

Best Plants for Large Aquaponics System

Tomatoes
Pepper
Cucumber
Beans
Squash
Peas
Broccoli
Cabbage
Strawberry

Components of an Aquaponics System

Main Components:

1. Fish

3. Plants

Select plan ts that are easy to grow and well suited to your location and climate. Until your new system is fully established, avoid planting nutrient-hungry plants like tomatoes and stick to easy-to-grow plants like leafy greens, lettuces, and herbs. Nutrient-hungry plants require many nutrients, and a new system may not be able to supply all the nutrients needed for these plants. Lack of nutrients in the system can result in nutrient deficiency to your aquaponics plants.

4. Bacteria

Bacteria convert fish wastes into nutrients absorbed by the plants. So it is essential to maintain a healthy bacterial colony in your system. The bacteria in an aquaponics system can be present in the biofilter, grow beds, and fish tanks.

Secondary Components

Fish Tank - The fish tank is the home of your fish and one of the most important materials of the aquaponics system.
Grow Bed- Will hold your plants and grow media. Depending on your system, the grow bed can be PVC pipes, floating rafts, or any food-grade containers.
Grow Bed Support- Frame that will support the weight of your grow bed.
Sump Tank- Optional. Using a sump tank will depend on the design of your system.
Plumbing pipes and fittings - It depends on the type of your grow beds, system, and other factors.
Bell Siphon - A bell siphon is required for a flood and drain media bed.
Water pump- The water pump size depends on your desired tank exchange rate and several grow beds.
Aerator, air stones - This is used in the fish tank and media beds.
Grow Lights- Optional. This is mainly used in indoor systems.
Heater- Optional. Using a water heater will depend on your location, fish species, and target water temperature.
Grow Media - You can use clay pebbles, expanded shale, gravel, and other inert media for a media-based system.
Monitoring System- Optional. It depends on your situation and how you want to manage your system.
Timers and Controllers- This is mainly used for lighting, pumping, and controlling the temperature.

Tips on Building an Aquaponics System

1. Learn How Aquaponics Works

Research is an essential aspect of aquaponics, and it will help if you research how an aquaponics system works. Find out what you'll need and how each part works. So that when you're ready to begin, you already have some knowledge about aquaponics. There are lots of free aquaponics reading materials and tutorials online. Watch videos of how others created their aquaponics systems and read blogs about aquaponics to learn from them.

2. Building Your System

Once you have chosen the aquaponics system method, you want to implement and gathered all the materials needed, you can start building your aquaponics system based on your specifications and design. The ultimate aquaponics beginner's guide is a great resource material in creating your system. If money is not an issue, you can purchase a ready-to-use aquaponics system kit that comes with instructions. Once your system is fully set up, test it to ensure no leaks and the flow rate and drain rate work well.

3. System Cycling

Before stocking your system with fish and plants, ensure your system is healthy by cycling to establish the beneficial bacteria. The cycling process converts ammonia (fish wastes) into nitrates necessary for the plants to thrive in an aquaponics system.

Cycling starts when setting up a newly built or restarting aquaponics system. Cycling with fish generally takes 4-6 weeks. For an in-depth discussion on system cycling, refer to the methods of cycling new aquaponics systems.

4. Aquaponics System Maintenance

Here are some tips on what you can do to maintain the proper conditions of your aquaponics system for it to be successful and produce a higher yield.

Ensure Adequate Aeration and Water Circulation

You can use water and air pumps to ensure that the water in your system has high dissolved oxygen levels. Having water or air pumps will also help give good water movement to the water in the system, suitable for the fish, plants, and bacteria.

Maintain Good Water Quality

To manage an aquaponics system correctly, every aquaponics grower must understand the basic water chemistry in order to get the most out of plants, fish, and bacteria. The five key water quality parameters that you need to monitor and control are; dissolved oxygen (5 mg/liter), pH (6-7), temperature, ammonia (0 ppm), and nitrites (0 ppm).

Avoid Overfeeding and Remove Uneaten Food

Feed your feed every day, but only feed the fish what they can consume in 5 minutes. Scoop out wastes and uneaten food to avoid water quality issues. Rotting food can cause fish diseases and can use up the dissolved oxygen.

Maintain Balance Between Plants and Fish

Applying a batch cropping system can help keep a steady harvest and help maintain a good balance between plants and fish.

Enjoy The Benefits

Be proud! You've done it. Your aquaponics system is established and thriving. Enjoy the fruits of your labor. Whether you're growing an indoor or outdoor aquaponics garden, your system will be a great addition to your home. Your family and friends will enjoy watching the fish grow and eat healthy fresh harvest from your yard.

Conclusion

Now that you have basic ideas about how aquaponics works and how it can benefit growers, food producers, and society as a whole. There's still plenty to learn, but hopefully, these ideas can help you become successful in your aquaponics endeavor. Thank you for reading our article. For more aquaponics systems design ideas, check our inspiring aquaponics systems designs that you can DIY.