Future of Farming – Aquaponics


Image source: (Fix.com)

AquaponicsThe Future Of FarmingOur Goal: To understand how an aquaponics system can be implemented within the Sahel Region of Africa and estimate the costs, energy use, and impact aquaponics would have on the region if it were to be scaled for the whole population there.
What is Aquaponics?
Aquaponics is an efficient system of growing food through the combination of raising fish (aquaculture), microbes and worms, and soil-less growing plants (hydroponics).

Waste from farmed fish (their poop) is converted to fertilizers to supply nutrients for plants to grow.

Meanwhile, the plants help filter the water for the fish, and in turn the naked roots from the plants are consistently supplied with water in a timed cycle.

An aquaponics system produces zero waste, recycles water, and removes the use of fertilizers or chemicals.


Image Source: (Fix.com)
Components of an Aquaponics System

Fish: Deciding which type of fish to raise largely depends on the environment the aquaponics system is in. If it is in a warm environment, choose fish that thrive in warmer water. However, the temperature of the aquaponics system can be controlled if it is built inside a greenhouse that traps heat inside.

Seeds: After deciding which species of fish will be raised, decide which plants to grow. The general rule of thumb: The more nutrients a plant requires to grow, the bigger and more productive the aquaponics system needs to be.

Tank: Essentially a container that houses the fish. The tank could be a clean, recycled food barrel or a glass aquarium.The most important thing to consider is that if the tank is capable of holding enough water for the fish; the more the better, so they have space to swim comfortably. Upon implementation of the aquaponics system its imperative to monitor how quickly the fish reproduce within the tank in order to calculate when the tank will reach its max fish capacity.

Grow Bed: The area where the plants grow. The grow beds can vary in structure and appearance, but one popular option is to use shallow wooden boxes lined with pond liner and perlite, gravel, or another soilless medium with excellent moisture retention and enough structure to provide plant support.

Bio-filter: A location where bacteria can grow and convert organic waste (poop), carbon dioxide, and ammonia into nitrates, which are nutrients for the plants.

Pumps: An aquaponics system requires an aerator to provide oxygen for the fish and a pump to send water from the fish tank to the filtration system to the grow bed and back again (unless you use gravity for the water’s return journey).

PVC Pipes: To pump the nutrient-dense water throughout the system.

Solar Panels (optional): The pumps need a source of energy in order to be powered and drawing energy off the grid with solar panels can will take aquaponics to a whole new level of sustainability and reduce energy consumption costs.


Image Source: (Fix.com)
What Grows Best With Aquaponics?
Leafy crops: Herbs, lettuce, kale, Swiss Chard, etc.

Plants: Squash, cucumbers, broccoli, cabbage, and cauliflowers. However, these plants require a very well established aquaponics system because they have higher nutritional demands.

Fish: Tilapia, bluegill, or koi. The more fish used in the system, the more luck with growing fruit plants such as peppers or tomatoes.

Aquaponics vs. Conventional
Aquaponics uses 90% less water than conventional farming. (Abundance.org)

Aquaponics has less of an environmental impact.

Aquaponics can grow produce faster and with 3 to 4 times more density compared to produce grown conventionally in the ground.

Aquaponics can be successful in various climates because it does not depend on soil conditions.

Aquaponics energy usage is from 70% to 92% less than a conventional or organic farm.
(Green Acre Aquaponics)

An aquaponics system does not require any soil, weeds, soil pests or pathogens.

Aquaponics has less labor involved than conventional farming (e.g. no more need for fertilizer spreading, compost shredding etc).

Only relies on electrical energy so it can be powered by solar, wind, and hydroelectric.

Ergonomically better because seeding, planting and most harvesting can be done standing and working at waist level.

The Cons of Aquaponics

Dealing with the fish can be difficult and unpredictable. Species must be able to live harmoniously. Also, fish must be able to live comfortably in the tanks.
Water tanks sometimes need to be heated or cooled in order to keep your fish comfortable and alive.

The initial setup costs can sometimes deter people from aquaponics. You have to invest in a tank, a filtration system, a pump, and the grow beds.

Technical expertise is required. You’ll need to know how to run the water pump, balance out the pH level in the water, plant the correct seedlings for the system, etc.

Higher chance of failure. Should the pump or the filtration system fail, there is a very real chance that your fish and your plants can die and then the whole system falls apart.

There has to be a steady supply of water and it needs to be filtered and aerated. Anaerobic conditions are unsuitable for fish.

Aquaponics is technically not a closed loop unless you grow your own fish food. Otherwise their will be a monthly input cost for fish food.

How to Grow Fish Food

Aerobic Biological Reactors(ABR’s) are a key component in the water recycling process of an Aquaponics production system.They provide for the biological conversion of ammonia.

This results in an ideal growing medium for Lemna minor which becomes fish food. Lemna is one of natures smallest flowering plants and contains 35-40% crude protein with a high concentrations of essential amino acids, folic acid, minerals and beta carotene pigments that provide a balanced and nutritional diet.

In the integrated tilapia and duckweed recirculating system, the fish and the waters of the tilapia growout ponds provide the nutrients upon which the duckweed will thrive. In turn, the duckweed removes unwanted nutrients and waste products from the system, converting the nutrients into plant biomass. This plant biomass, in turn, becomes a high protein food for the fish. While all this is going on, water within the integrated system is conserved and purified. The entire system is a natural and sustainable approach to aquaculture.

The impact of ABR’s and Lemna to the system are:

  • Clean recirculated water returned to the fish reservoir.
  • Highly effective nitrate conversion.
  • Complete reduction in the cost of fish feed.
  • Reduction in management, labour efforts, and costs.

Provide education and training programs to develop farmers’ technical capacity.

Introduce and support aquaponic systems to households and establish demonstration units.

Introduce an aquaponic system, using simple and locally available materials including plastic containers, gravel, pumps and plumbing; and only establish aquaponics where there is consistent electricity and access to plant seed and fish seed.

Demographics of Sahel

Sub-Saharan Africa has experienced a rapid growth in population, even though most of the world’s population rates have begun to decline. This increase in population, most notably in the Sahel Region of Africa, will most likely lead to agricultural production difficulties, along with other challenges.

sahel-map (1).jpg

Collectively, the countries that make up the Sahel region (Burkina Faso, Chad, Eritrea, The Gambia, Guinea-Bissau, Mali, Mauritania, Niger, Senegal, and Sudan) have close to 135 million inhabitants, and span over 7 million square kilometers. The Sahel region’s GDP per capita is approximately between US$900 and US$3,000 per capita, a relatively low number that stems primarily from oil and minerals. Because the income from these oil and minerals puts most of the region’s wealth in fewer hands, the majority of the Sahel people tend to have a much smaller income.

More notably, these nations also have a record of being anti-business, primarily due to their history of political instability. Roughly half of the Sahel nations are categorized as fragile states, or low-income countries with very weak state capacity. This may become an important factor if/when aquaponics becomes implemented into the Sahel region, since businesses will likely have to invest.

One of the strongest reasons for Sahel to reinvent its agriculture – and specifically consider aquaponics – is its rising population growth. As annual demographic growth rates fall between 2.5% and 4%, the population should continue to grow beyond the region’s capacity. This population growth is due to the rapid decrease in infant and child mortality, but increase in fertility. Fertility rates average from 4.1 to 7.6 children per woman. By 2050, the region may have increased from 135 million today to 330 million, and 670 million by 2100. If the population does increase at this rate, the land will be unable to sustain its people through traditional agriculture methods.

Now while the key solution to this population problem primarily concerns improving female education, access to contraceptives, and raising the legal age of marriage, these actions take time. Introducing aquaponics to the Sahel region might provide an agriculture solution that compliments further attempts to slow population growth.

Screen Shot 2017-02-15 at 12.45.45 PM.png

Economics of Aquaponics

Screen Shot 2017-03-12 at 5.55.42 PM.png

Due to rapid poverty level in the Sahel, it would be very beneficial to implement an aquaponics system that would allow for more people to have greater access to food. As seen in the above image, roughly 80% of people in the Sahel region live on less than $2 a day. With poor farming land, and an unstable political region, it is often hard to establish long- term agricultural practices. An implementation of Aquaponics would allow for a quick solution to the food scarcity that the Sahel region faces.

Aquaponic Resources in Sahel

Sahelian Agriculture holds insufficiently utilized assets, including:

  • A large diversity of ecosystems, a potential source of diversification of production
  • Only 24.6% (or 2 hectares) of arable land is being used, and less than 10% of irrigable land has been developed
  • Regional market includes nearly a quarter of a billion customers

Water availability:

  • Less than half the population of the Sahel has access to water, while its demand increases with rapid population growth
  • The resultant threat to health and livelihood is set to become worse with desertification likely to increase by 5-8% by the 2080s
  • When rain falls in the Sahel, it can be so intensively localized that is can cause flooding and destroy crops
  • St. John Day, Water Resource Manager for Oxfam in Niger: “We’re getting the community to install simple groundwater loggers so they can measure and monitor how much water is available season to season underground. They also record rainfall levels, and analyze if they can improve rainwater usage and irrigation systems… [Communities also decide] which crops can be grown based on water actually available, not on assumptions of supply.”


  • Eden Aquaponics: Intends to become a major player in the aquaponic farming environment and be the main supplier of aquaponic equipment and ancillary resources in South Africa. Also strives to develop a community of aquaponic farmers in order to feed the nation.
  • Eden Aquaponics has a commercial farm, based between George and Uniondale in the Western Cape. The farm currently has 2 greenhouses measuring 925 meters squared with vegetables, and between 600 kg to 1000 kg of Tilapia fish.
  • The farm will be the cash generator of the venture, and will allow Eden Aquaponics to work towards its goal of implementing Aquaponics into South Africa. The farm will also be used for training of staff for projects across the country.
  • Although not in the Sahel Region, Eden Aquaponics is a closer resource than a supplier outside of Africa.
  • MyAquaponics: A website that offers Aquaponics and Hydroponics supplies, together with useful resources for the South African Community. Launched in 2011 by Aquaponics and Hydroponics professionals.

Cost of Aquaponics in Sahel

All calculations are based off an aquaponics system with a 3,400 liter tank and a 4 meters squared growing bed. Prices were taken from South African Aquaponics supplier, MyAquaponics, which is one of the closer and more reliable Aquaponics suppliers for Africa. All prices are written using the US dollar.
3,800 liter fish tank with 4 meters squared of growing space: $227.96
15W UV Sterilize (to kill harmful algae that develop in really hot climates): $82.54
Air tubing: $8.49
Air Stone: $3.85
28W Water Pump: $23.43
17W Air Pump: $117.83
Volcanic Gravel (biofiltration medium): $140
Miscellaneous items (fish net, plumper’s tape, shading, etc.): $100
Plumping (pipe, pipe fittings, connections): $90
60w Solar Panel(Gumtree.com): $125.92

Total Equipment Cost: $920.02

Plants (Seedlings): $4.60 per 46 seedling/month
Note: 46 seedlings is the average reseeding rate per month for 4m squared of growing space
Fish (Tilapia Fingerling): $3.93 for 5 fingerlings/month
Fish feed(If you do not grow it): $8.65 for 5kg/month
Monthly input supply cost: $17.18 per month

[28W (water pump) + 17W (air pump) + 15W UV sterilizer] x 24 hours x 30 days / 1000 = 43.2 kwh per month = 155.52 MJ

Electricity on the grid: $.16 per kWh

Monthly cost: $.16 x 43.2kwh = $6.91 per month

Solar Panels would pay themselves off after 18 months.

Food production: 20 lettuce heads per meters squared

20 x 4 = 80 lettuce heads monthly, or 960 lettuce heads annually
1 lettuce head = $1.20
960 lettuce heads = $1,152
Lettuce head worth – Annual input cost
$1,152 – $206.16 = $945.84 revenue annually assuming solar

Lessons the Food & Agriculture Organization of the United Nations Learned

Many of the poor households in Ghana that the FAO targeted first in implementing aquaponics, lacked the resources to continue buying inputs and farming experience to produce quality crops.

When independently running, they did not have access to local technical support.

So first work with families that have the farming experience to ensure that the aquaponics enterprise is profitable and sustainable within the local context.

Once these households have built their capacities and have developed successful working models, future projects can include other interested families who can rely on technical support from an existing local network.

Payoff of Aquaponics in Sahel


Our plan is to continue studying and invest in aquaponic companies in South Africa to help people grow their own food and create profitable businesses. Aquaponics can improve the lives of people in the Sahel regions; their heath and food security while creating self-sustaining income in one of the poorest communities in the world. The implementation of Aquaponics in the Sahel could serve as a means to help get a community out of poverty, rather than it solely being a charitable handout. With this innovative technology, it could help provide stability in an unstable region.

Team Members

Irene Uy: Irene is a Fourth-Year Environmental Earth Science major at Cal Poly. She is originally from Los Angeles, California but loves the small-town atmosphere of San Luis Obispo. Irene is most interested in sustainability, chemistry, and responsible resource use and enrolled in PSC 320 to further her knowledge. In her spare time, Irene does aerial silks, discovers new recipes to cook, and draws. After college, Irene would like to pursue a career in sustainable outreach in the entertainment industry.

Ariana Torres: Ariana is a third year Electrical Engineering major at Cal Poly. She is originally from Templeton, CA- about 20 minutes from San Luis Obispo. Ariana is most interested in Electronic Systems Security as well as the environmental impacts of hardware in our electronics. In her spare time, she watches The Price is Right, plays tennis, fences, and enjoys getting sleep! After college, Ariana hopes to work in the Hardware Security Industry.

Christian Barreto: Third year Liberal Arts and Engineering Studies (Graphic Design + Industrial Engineering) major at Cal Poly. I was born within the infamous and misrepresented South Central side of Los Angeles. I’ve Inherited nothing but the dreams and hard work ethic from my parents who immigrated to the United States to give me a chance at a wealth of opportunities. I am determined to climb the mountain of Capitalism to pull my family out of poverty. However, I aim to contribute my knowledge towards the developing world and clean energy.

Nikki Libby: Nikki is a third year Graphic Communication major at Cal Poly, concentrating in Design Reproduction Technology. She is originally from Carlsbad, CA, a beachside suburb near San Diego. Nikki is most interested in graphic design, but also enjoys learning about forensics, printed electronics, and biotechnology. Following college, Nikki plans on pursuing a marketing career within the biotech field.


If you didn’t make your diagrams, please reference the origin.

By and large, great work! Lots of information. I don’t like your costs so much… I encourage you to innovate a little. Why would someone pay $200 for a tank, when $10 would buy enough plastic to line a hole in the ground. Solar panels cost much less than you have there. Why is there a UV sterilizer? Can you get $1.20 for a head of lettuce in the Sahel? I would bet you can’t. Do you need 80W? Please give this some thought.

Can you provide references or support for these statements. What fraction about of water use than conventional farming?

Can you provide references or support for these statements. What fraction about of water use than conventional farming?This is interesting. Where do you know this from? Why is it that there is less energy used? Your system seems energy intense to me, but maybe I’m missing something.
What does “FAO” mean… Food and Ag? Please make this clear the first time you use the Acronym.