What is Aquaponics: A Very Fertile Beginner’s Guide


A beginner’s guide to Aquaponics: what it is, what you need, and why it’s important. We discuss the history of aquaculture and hydroponics, as well as the components you’ll need to start your own Aquaponics system.


Updated: November 14, 2023
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Aquaculture is a particular type of farming that involves cultivating different fish species and has been practiced throughout history.

Hydroponics is an innovative method of growing crops in water instead of soil.

The wonderful combination of these two methods of farming is known as Aquaponics.

In this article, we'll cover:

  • A clear explanation of exactly what Aquaponics is
  • A brief history of Aquaponics and its origins
  • A detailed explanation of the science and mechanics involved in an aquaponic system as well as the different types of systems that exist
  • The components that make up an aquaponic system and the basics of operating it
  • The benefits and reasons why Aquaponics is a revolutionary system of gardening that everyone should learn about










So, what is Aquaponics?



Aquaponics is a system of agriculture that incorporates two different types of agriculture – aquaculture, and hydroponics, hence the name ‘Aquaponics,’ a combination of the words ‘Aquaculture’ and ‘Hydroponics.’

Aquaculture deals with farming aquatic animals such as fish, prawns, crayfish, and snails using tanks, while hydroponics involves cultivating plants in water.

Aquaponics combines these two types of agriculture in a symbiotic environment where plants and animals benefit from one another to thrive and grow.






A Brief History



aztec-chinampa-anthropogen

Aquaponics is a relatively new branch of modern agriculture, as the term itself only came into being in the 1970s. But the two farming methods from which it sprouted have been around for centuries. The earliest example of hydroponics dates back to around 1000AD when the Aztecs cultivated plants on rafts on the surfaces of lakes. Aquaculture was performed separately in vast ponds and required large quantities of water and land (Palouse-Clearwater).

Aquaculturists discovered that the nutrients excreted in fish waste were a perfect fertilizer for hydroponic plants, and thus, the idea of Aquaponics was born. Through modern technology, innovative pumping systems cycled the fertilized water properly, allowing Aquaponics to become what it is today.











How Aquaculture and Hydroponics Work Together



Aquaponics and woman


While Hydroponics is certainly a modern agricultural marvel, it does have some limitations. It requires large amounts of costly nutrients and regular flushing at precise intervals to dispose of waste.

Aquaculture requires that excess nutrients be regularly removed from the system and replaced with fresh water or risk harm to the fish.

Aquaponics combines these two systems so that each need is met. Here, the plants are purifying the water for the fish while the fish are providing food for the plants. A perfect match.











The Aquaponic Cycle



aquaponics diagram 1



Aquaponic systems vary in size. Larger commercial systems can incorporate thousands of gallons of water, producing hundreds of pounds of crops. Home aquaponics units can produce a few pounds of vegetables with a 50-100 gallon tank and only several fish.

Regardless of the size of the system, the components are reasonably the same.

An aquaponics system requires a water pump, a grow bed, fish, fish food, and a tank.

Fish thrive due to the purified environment that the plants provide. After eating, the fish excrete waste that contains ammonia. In a closed tank, prolonged exposure to ammonia will kill the fish and must periodically be flushed out.

The beauty of Aquaponics is in the ability to convert waste from one organism into food for another.

Bacteria in the soil of the grow bed can break down ammonia into nitrites and nitrates. In this form, plants can absorb these nutrients as fertilizer, promoting more growth than with soil alone (Pattillo, 2017).

After the ammonia-concentrated water is pumped to the grow bed and absorbed by the plants, the water is now ammonia-free and can now be cycled back into the fish tank.

The water now becomes clean and fresh enough for fish to thrive, and the cycle starts again.



aquaponics diagram 2

Water pump

An electrical source is required to operate the water pump, which is the force that cycles water throughout the system, flushing ammonia-concentrated water from the fish tank and transporting it to the plants.

The pump also oxygenates the water for the fish, providing a thriving environment for them. The fresh, filtered, and oxygenated water is then recirculated to the fish tank, where the cycle begins again.

Sunlight

Whether natural or artificial, plants need a light source to grow. Many aquaponics systems can operate outdoors underneath the sun, but most are operated indoors in a controlled environment with artificial lighting.

Feed

Another external element that is required to sustain an aquaponics system is fish food. Proper diet and regular feeding of fish are critical in ensuring a well-operated system.











Components of an Aquaponic System




Grow Bed



growbed

growbed

This rectangular box is what holds and raises the plants. They're typically made of food-grade, recycled plastic of a dark opaque color. The dark color plays a role in absorbing heat, which warms the soil while retaining moisture to help plants grow.

The grow bed contains some type of media, typically soil or pellets, in which the plant seeds are placed. The media itself contains bacteria which convert ammonia into plant food.






Tank



outdoor fish tank

outdoor fish tank

The tank is where fish will be kept and can vary in size depending on the species and number of fish. Tank sizes range from 5-gallon tanks, holding a few small fish for personal use, to thousand-gallon sizes for commercial use. The tank material is usually an opaque, food-grade, polyethylene plastic.






Fish



blue fish

blue fish

Fish play a vital role in the aquaponic system because they provide nutrient-rich plant food in the form of waste. The selection of fish species is critical when starting an aquaponics system since certain species have certain requirements.

Factors such as water temperature, pH level, feeding schedule, and waste composition all affect the system's overall function. The best species of fish is the one that is best suited for the desired crop being cultivated.

Edible fish, such as bass and trout, can provide another food source besides the crops. Ornamental fish, such as koi, cannot be eaten but only serve as a means of providing nutrients for the plants.






Plants



butter lettuce

butter lettuce

Harvesting lush vegetables from an aquaponics system is the end goal of the entire operation, and the variety of crops that can be harvested is wide. Aquaponic systems are ideal for leafy plants such as lettuce, mint, chives, basil, lettuce, and kale. Plants with higher nutritional demands, such as peppers, beans, peas, cauliflower, tomatoes, broccoli, cucumber, and cabbage, do better with well-established systems.

Other crops grown in aquaponic systems include carrots, beets, radishes, lemons, limes, onions, sweet corn, and other edible flowers (Nelson and Pade).

Due to the nutrient-rich fertilizer the fish provides, aquaponics vegetables tend to grow larger and healthier than in soil alone.

Plants also play the critical role of purifying the water of ammonia and providing clean water back to the fish.







Bacteria



waterborne diseases

bacteria / creative commons

The soil in the grow bed contains bacteria that serve a vital function: to break down ammonia. If not broken down, ammonia can harm both fish and plants.

When ammonia-concentrated water is flushed into the grow bed, the bacteria in the soil convert it into nitrites and nitrates. In this form, plants can use it as fertilizer to help them grow. The water is then flushed back into the fish tank, now ammonia-free.







Operation and Maintenance



aquaponics system


  • The condition of the water is critical to a successful aquaponics system. Factors such as water temperature, pH level, and water hardness can all affect the quality of the plants and fish.
  • Fish food is one external element that must be added to the system for it to operate. Ensure the fish receive high-quality food on schedule, according to the fish species.
  • Check your fish tank’s temperature daily, as it is essential to create the ideal environment for the specific aquatic species you have. Some fish require colder temperatures, and others may require warmer temperatures.
  • Check your system for insects regularly, as tackling insect problems early enough before they become uncontrollable is easier and safer for plants and fish.
    • Check the system’s nitrate levels regularly. A spike in nitrate levels might mean that there aren’t enough plants to absorb the nitrogen that is being converted by the nitrifying bacteria. You can solve this problem by adding more plants, adding a new grow bed to your system, or reducing the number of fish you have.
    • Check all pumps and plumbing daily and clean them at least once a month to allow for adequate circulation. Run a hose of high-pressure water through every component of your system.





    Types of Aquaponics Systems



    While all aquaponics systems follow the basic principles discussed above, there are varying ways to set up an aquaponics system. Here are the four main types.




    Raft Based / Deep Water Culture (DWC)



    Aquaponics Raft

    Deep Water Culture aquaponics is common for commercial use and accommodates the growth of large amounts of plants.

    With this system, plants are grown aboard rafts (usually polystyrene boards) floating on water in a separate tank from where the fish are kept. Water is circulated between both tanks with a pump. Nitrifying bacteria are added to the raft tank to help with ammonia conversion.

    One significant benefit of the raft system is the ability to separate newer plants from harvest-ready plants, which can be convenient for larger aquaponics systems. Raft with seeds can be planted on one end of the raft tank while mature plants can be harvested on the other end, making the process of planting and harvesting much easier.






    Media-Filled Bed



    Media filled aquaponics

    The media-filled grow bed is the traditional method of aquaponics and is much more common with residential use. They tend to be smaller and more manageable than deep water culture systems.

    The grow bed is filled with some type of media containing perlite, gravel, or soil. On a regular schedule, water is pumped from the fish tank into the grow bed and then flushed back into the fish tank when the water has been purified.

    Media-filled grow beds can be customized to one's preference, varying in size, shape, and material.






    Nutrient Film Technique (NFT)



    NFT Hydroponics

    With NFT aquaponics, plants are grown in long, narrow channels where a constant flow of shallow water from the fish tank flows down each tube, providing the roots of the plants with specific amounts of nutrients, water, and oxygen.

    This technique is beneficial for specific types of plants that require very controlled conditions. It requires less water than DWC or media-filled beds but will have a lower crop yield.






    Vertical Aquaponics



    hydroponics vertical

    Like NFT aquaponics, vertical aquaponics utilizes water very efficiently and allows for better environmental control for plants with specific requirements.

    One particular advantage of vertical aquaponics is that it utilizes space efficiently and is ideal for urban settings where space is limited. The fish tank is placed at the bottom of the system and plants are arranged in vertical tubes above.












    Benefits to Aquaponics



    vegetable greens

    • Aquaponics uses about 90% less water than soil-based gardening since the water in the system is recirculated. As a result, only water that evaporates or water absorbed by plants is replaced. This, in turn, makes water available for other uses and reduces the amount of water wasted on cultivating crops (Common Sense Home, 2017).
    • Aquaponics is an inexpensive means of agriculture. Apart from major equipment and components like tanks, filtration systems, grow beds, plants, and fish, it uses little input to produce two crops (fish and plant). Electricity costs are also significantly reduced as it requires only energy to run pumps and oxygenate fish.
    • Aquaponics produces far more organic plants than soil-based cultivation. It doesn’t use pesticides and chemical fertilizers, which can be hazardous to fish and other aquatic species.
    • Aquaponics can produce more on a single square foot than with soil-based cultivation. This is because plants grow 2-3 faster than on soil. Also, plants can be packed twice as densely on the ground.
    • It is easy to set up and can be set up indoors and outdoors. It can also be used anywhere as it does not depend on soil fertility. As such, it can be set up in places such as schools, restaurants, garages, and home basements.
    • Finally, it gives you the satisfaction of growing and eating your fish and vegetables!





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    References

    The Aquaponic Source. (n.d.). What is Aquaponics. Retrieved from https://www.theaquaponicsource.com/what-is-aquaponics/

    Aquaponics System Solutions. (n.d.). DIY Aquaponics And How To Easily Build One. Retrieved from http://www.aquaponicssystemsolutions.com/

    Common Sense Home. (2017, October 30). Introduction to Aquaponics: Growing Fish and Vegetables Together. Retrieved from https://commonsensehome.com/introduction-aquaponics/

    Nelson and Pade. (n.d.). Methods of Aquaponics. Retrieved from https://aquaponics.com/methods-of-aquaponics/

    Nelson and Pade. (n.d.). Recommended plants and fish. Retrieved from https://aquaponics.com/recommended-plants-and-fish-in-aquaponics/

    Palouse-Clearwater. (n.d.). Introduction to Aquaponics. Retrieved from https://pcei.org/living/living-com-resources/permaculture/aquaponics/

    Pattillo, A. (2017, March). An Overview of Aquaponic Systems: Hydroponic Components. Retrieved from https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1018&context=ncrac_techbulletins

    Wikipedia. (2018, July 3). Aquaponics. Retrieved from https://en.wikipedia.org/wiki/Aquaponics