Lauryn Srethbhakdi, 9B

Are Aquaponic Systems Sustainable?

The main issue during 21st century is the increasing population. There are at least 10 times more

people in the world than three centuries ago and it is predicted that the population will reach 9 billion

people in half a century. As a result, food production systems would need to produce 50% more food by

the next half century in order to meet the world population’s growing demands (United Nations).

Environmental awareness has created increased consumer interest in locally grown, sustainable food

production systems, while advances in technology continue to improve farming productivity and

efficiency, it still requires a large amount of two very precious natural resources, water and land.

However, there is a food production system that utilizes roughly 2% of the water used on a conventional

farm, called aquaponics. This system combines the practices of aquaculture, raising fish in freshwater and

hydroponics, growing plants in a soilless environment to produce both plant and protein crops (Colle &

Phyllis). This essay will demonstrate how the nitrogen cycle is essential in aquaponics, the inputs and

outputs, whether this food production system is sustainable and the economical impacts.

Figure 1: Aquaponics Systems Diagram (self-made)

From Figure 1, it can be seen that a large portion of the input is based off of human effort and

holds costly inputs to produce a smaller outcome, but as a result, larger stocks of protein and vegetables

are produced. Human contributions include replenishing water due to run off and evaporation during the

INPUTS- Light ( Artificial / Natural )

- Electricity- Fish Food

- Water ( H2O )- Oxygen ( O )

- Carbon Dioxide ( CO2 )- Growing Medium ( perlite,

ceramic stone )- Iron

- Plant Seeds

PROCESS- Nitrification ( Biofilter )

- Photosynthesis- Respiration ( plants and

fish )- Mineralization

- Pumps ( circulate water between tanks )

- Temperature control- Absorbment ( absorbing

nutrients for plants )- Plant transpiration

STORAGE- Biomass

OUTPUTS- Protein ( fish )

- Plants / Vegetable ( hydroponics )- Oxygen ( O )

- Carbon Dioxide ( CO2 )- Gluecose

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recirculation of water, extra micronutrients, such as iron and magnesium, may have to be added to keep

the plants healthy, and it is necessary to feed the fish constantly in allowing them to grow, but

furthermore allowing them to produce waste. A source of lighting is crucial in the process of

photosynthesis. Therefore, Figure 1 has respectively shown that the inputs outweigh the outputs.

In an aquaponic system, it is vital in the removal of harmful waste products and uneaten food from

the aquaculture system. Fish excrete large amounts of ammonia through their urine and gills, also from

their solid waste, as it breaks down through a natural biological process in which heterotrophic bacteria,

a natural bacteria already present in the water, converts the solid waste to ammonia, toxic to fish and

aquatic organisms. In the tank, fish are stocked densely resulting in higher levels of ammonia than in a

saltwater-based ecosystem. Instead of disposing this material, which an aquaculture system would

essentially perform, aquaponics utilizes the waste material in the growing of plants in a hydroponic

setting. The waste product enters a bio-filter (see Figure 3), a sector of the system, which allows for

nitrification to occur (see Figure 2). Two types of bacteria in the water will convert the ammonia to

nitrate using oxygen in a two-step process. The bacteria, known as nitrosomonas converts the toxic

ammonia (HN3) to nitrite (NO2-) and nitrobacter, another bacteria converts the nitrite to nitrate (NO3-)

(Nelson, 2008). Ammonia and nitrite are both toxic to fish, though nitrate is less toxic and can be

controlled through cultured species. The control of nitrate in aquaponics is completed through

Figure 2: Nitrification Process taken place in Aquaponics (Brown's)Figure 2: Nitrification Process taken place in Aquaponics (Brown's)

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hydroponics as the water containing nitrate moves to the grow beds, which filters out the nitrogenous

compounds that are toxic to the fish.

Figure 3: Aquaponics Cycle diagram (Veggi, 2012)

This food production system is not sustainable in a way as to which uses human input, as needing

to consistently monitor the system. Aquaponics includes both positive and negative aspects when

determining whether or not it is a sustainable system. The constructive elements, includes being able to

provide a large stock of protein and vegetables at a rapid rate as to which is because the system is

designed to tolerate the growth of plants and fish in a climate not typically associated with farming (The

Aquaponics Association). The design has also maximized space through the stacking of grow beds as

space becomes beneficial and areas are heavily urbanized, though this requires for the most constant

plumbing, but the investment will allow for more plant production. In doing so, the downfall in keeping a

sustainable aquaponic system includes the recirculation of water (see Figure 3), as run-off, evaporation

and transpiration of plants will occur in the system, as a result, it is necessary to replenish the water

supply. The circulation of the system and maintaining the temperature, results in high-energy

consumption. Moreover, 90.7% of the world’s energy is nonrenewable and most aquaponic systems rely

on this unsustainable supply of energy (Lallanilla, 2013). Making sure the building or household is well

insulated will reduce energy consumption. Because aquaponic systems are able to maintain itself in harsh

climates and are designed to survive in the dark due to artificial lighting, the system could support itself

through natural lighting. Trapping the light in a greenhouse would maintain the temperature whilst,

reducing the amount of energy consumed and decreasing the energy cost.

An aquaponic system reduces the environmental footprint in crop production. Although, this

system requires electricity and water for fish and crops to be controlled in an indoor ecofriendly

symbiotic environment, the environmental impact of aquaponics is negative and positive, based on how

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the system is designed and the natural biological processes. An aquaponic system relies on electricity to

create the symbiotic relationship between fish and plants and 200 watts of electricity is essential in

running the pump to circulate the water (How to Choose a Good Aquaponics Pump). Energy cannot be

produced without the use of natural resource (Environmental Impact by Energy Source). The more

energy that is required, the faster the resources deteriorate. Approximately 82% of the world’s primary

energy use comes from burning fossil fuels and the burning of this material results in releasing harmful

gases including carbon dioxide, monoxide, sulfur dioxide, nitrogen oxide and hydrocarbons. The gases

are released in the atmosphere that contributes to the greenhouse gases as carbon dioxide, significant in

trapping heat in the atmosphere (Kushner). Aquaponics allows for the removal of chemical fertilizers

and pesticides as the fish provide natural fertilization for the plants (Beenish & Abu, 2013). Agriculture

uses up approximately three quarters of Earth’s accessible water, but because aquaponics runs as a

recirculating system, the only water lost is through transpiration of their leaves, evaporates or through

runoff. This system uses less than 10% of the water used on a traditional agriculture farm for the same

crop output (Boulder, CO, 2011). Conventional farms dispose at least a third of their crops due to the

contamination of pests, but aquaponic systems are designed to raise the grow beds, to allow for

gravitational flow of water entering the fish tank, accordingly, tend to have fewer pests than traditional

agriculture systems. This system also reduces the consumption of petroleum as it could be set up

anywhere, producing food directly in urban areas. As a result, the course from a farm to a table is

accessible in local areas (Boulder, CO, 2011).

An aquaponic system essentially is a food production system, which operates due to the symbiotic

relationship between the plants and fish. This system has been designed to allow an aquaculture system

to provide an organic fertilizer for the hydroponics as to which filters out the toxic water and provides

clean water to the fish tank, through the nitrogen cycle. Accordingly, the output of the cycle is due to the

input of human energy as they replenish the water supply, feed the fish and provide micronutrients to

maintain the fish and plants. Aquaponics could potentially be the farming of the future as to which has

allowed people to cultivate crops in area, which is not usually correlated to agriculture. This system has

been designed to conserve space, beneficial to urban areas. Alongside, aquaponics is sustainable in

recirculating the water using only a portion of a conventional farm. Though, this system has downfalls as

the system consumes large amounts of energy. An idea implemented in creating a more sustainable

aquaponic system is the use of natural light and insulating the area in a greenhouse, resulting in creating

a more sustainable food production system, which creates opportunities to provide the world’s

population with a manageable food supply.

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Works CitedBeenish, A., & Abu, D. (2013, May 13). Aquaponics Expert Brings Sustainability to the Desert. (A.

Leslie, Editor, & UAE, Producer) Retrieved March 21, 2014, from DW: http://www.dw.de/aquaponics-expert-brings-sustainability-to-the-desert/a-16808762

Boulder, CO. (2011, October 21). Aquaponics Solves Agricultural Environmental Problems While Increasing the World’s Food Production. Retrieved March 23, 2014, from PRWeb: http://www.prweb.com/releases/aquaponics/environment/prweb8895377.htm

Brown's. (n.d.). What is Aquaponics? (Blogger, Producer) Retrieved March 25, 2014, from Farmer Brown's Aquaponics: http://farmerbrownsaquaponics.blogspot.com/p/what-is-aquaponics-primer-for-newcomers.html

Colle, D., & Phyllis, D. (n.d.). What is Aqaponics? Retrieved March 20, 2014, from Portable Farm: http://portablefarms.com/what-is-aquaponics/

Environmental Impact by Energy Source. (n.d.). Retrieved March 20, 2014, from Energy4Me: http://www.energy4me.org/energy-facts/environmental-protection/environmental-impact-by-source/

Gith, T. (2013, August 4). Sustainable farming project combines aquaculture and hydroponics. (C. Chimbelu, Editor) Retrieved March 19, 2014, from DW: http://www.dw.de/sustainable-farming-project-combines-aquaculture-and-hydroponics/a-16927582

How to Choose a Good Aquaponics Pump. (n.d.). Retrieved March 22, 2014, from Aquaponics Systems: http://aquaponics-system.com/440-how-to-choose-a-good-aquaponics-pump/

Kushner, J. (n.d.). Fossil Fuels Bad? Retrieved March 20, 2014, from Bionomic Fuel: http://www.bionomicfuel.com/why-are-fossil-fuels-bad-for-the-environment/

Lallanilla, M. (2013, June 27). What are Greenhouse Gases. Retrieved March 20, 2014, from Live Science: http://www.livescience.com/37821-greenhouse-gases.html

Nelson, R. L. (2008). Bio Filter. Retrieved March 20, 2014, from Aquaponics Journal: http://aquaponics.com/media/docs/articles/Aquaponic-Equipment-The-BioFilter.pdf

The Aquaponics Association. (n.d.). Why Aquaponics? Retrieved March 22, 2014, from Green Acre Aquaponics: http://www.greenacreaquaponics.com/why-aquaponics/

United Nations. (n.d.). How to feed the World in 2050. (United Nations) Retrieved March 21, 2014, from Food and Agriculture Organization: http://www.fao.org/fileadmin/templates/wsfs/docs/expert_paper/How_to_Feed_the_World_in_2050.pdf

Veggi. (2012, October 5). Aquaponics - A Brief Introduction. Retrieved March 20, 2014, from Veggi's Farmer Cooperative: http://www.veggifarmcoop.com/2012/10/05/aquaponicsintro/

Exact Word Count (excluding systems diagram text,

in-text citation and bibliography): 1156

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