Water conservation is one notable feature of aquaponics. This food production system recirculates water throughout the tanks and growing beds which means there is not much water usage compared with conventional farming methods. At first, the grower will use gallons of water to fill in the fish tanks, but water for refilling purposes will not be that much in the long run.
How does aquaponics work?
Aquaponics is a method of feeding fish effluents to plants. Water is an essential component of aquaponics; it sustains the plants and aquatic critters in any aquaponics system. In this food production methodology, water is used as a medium. From the fish tank to the plant bed, water circulates continuously.
Water is regularly replaced in traditional aquaculture and hydroponics systems. This practice is unsustainable in the long run. Water wastage is a huge environmental and social issue that requires immediate critical attention in a world where water scarcity is increasing.
This farming approach has several advantages, including the fact that it lessens the food miles of food products. Note that aquaponics is a form of urban gardening. This means that fish and vegetables are produced within the community and do not need to travel great distances to reach the markets and grocery stores.
For this post, we will touch upon aquaponics' ability to save water significantly.
Is aquaponics environment friendly?
One of the significant advantages of aquaponics is its sustainability. The word refers to avoiding the depletion of natural resources to achieve ecological balance and allow succeeding generations to utilize them for their own survival. Thus, a sustainable food production is characterized by being environment-friendly because the environment has the natural resources every generation of humans needs. Aquaponics does many things to preserve our limited resources, such as soil and water. Here are some reasons that support aquaponics' sustainability:
- Aquaponics does not require acres of land to operate. You can build any type of aquaponics setup on various terrains and locations. From a home's backyard to an unused warehouse, these places are ideal for aquaponics. As a result, land areas are preserved and used for other purposes aside from producing our foods.
- Aquaponics practitioners avoid the hassles soil farming brings. One of which will be the management of weeds. Because you are not using soil to grow your plant produce, there is no need for you to deal with weeds that rival plants of vital nutrients. Consequently, the plants are spared from applying harmful chemicals that deal with weeds.
- Aquaponics does not need much water in order to sustain the plants growing in it. Growers can obtain a 95 to 99% water re-use efficiency in an aquaponic system. This claim is according to a study done by the University of Gothenburg. Now, compare this water usage efficiency with traditional farming wherein farmers use 70% of their water supply for irrigation purposes.
Read this post for a more thorough discussion about aquaponics as an environment-friendly approach to food production. (Link to article)
How does aquaponics save water?
Aquaponics is classified as a type of recirculating aquaculture system (RAS). The term "recirculating" hints at how aquaponics manages to save significant amounts of water compared with its food production contemporaries. The water used for the fish tanks and grow beds travels across the aquaponic setup. Pumps are utilized to run the water across the components of the system.
Fish waste products are transferred to the plants because they will use these to obtain the nutrients they need for growth. In turn, the water is filtered and then returned to the fish tank. This process is continuous, which explains how aquaponics does save water. To better manage the water within the system, biofilters and sump tanks are added.
Now, there is also water loss in aquaponics, but this is very minimal. Whatever amount of water is lost in the setup, this could be attributed to the following:
- Waste removal - The wastes mentioned here are the solid ones that get into the sump tanks or mechanical filtration.
- Evaporation - This process is determined by the water's surface area, ambient temperature, and airflow across the water. Usually, during summer, the evaporation rate of your system will be at its peak.
- Evapotranspiration - This is a natural process wherein the plants themselves lose water through their leaves.
- Plumbing and tank leaks - There will be instances that you will have leaks in your plumbing system, leading to water loss. Tank leaks are also possible if the construction material of the tank is not durable enough.
How to minimize water loss in aquaponics?
Even though water loss in aquaponics is not much of a great concern, it is still wise and practical to follow specific steps to minimize its occurrence. Here is a short list of ways you can do to help lessen the amount of lost water in your system:
- Conduct a routine maintenance check of your system. One of the things you will look for is the presence or possibility of leaks to your pipes and tanks.
- Apply float switches to your sump tanks. Float switches control the water pump and keep it from releasing all of the water. To avoid a vast quantity of water loss, the float switch on the sump tank will automatically cut off once the target water level is reached.
- When summertime arrives, you may apply some shading to your greenhouse to lessen the amount of sunlight. By so doing, you can minimize the evaporation rate within your aquaponics setup.
- Do check your water temperature because high temperature makes the plant work harder. Thus, they transpire and lose more water.
- If your aquaponics system is in the open, make sure you surround it with a fence to keep stray animals. Their presence does not only lead to the destruction of your crops but the leakage of your plumbings and tanks.
Can you use rainwater in aquaponics?
The answer to the above question is a definite, "Yes!"
In aquaponics, you can use rainwater to fill the fish tanks. This is another excellent reason you can save water as you adopt aquaponics. Note that it is potable water that is fresh, pure, and free of contaminants. Rainwater is even free, and collecting it will help you save money, making your aquaponics system more sustainable. Since rainwater has a salinity level of virtually zero, it is ideal for aquaponics systems to prevent long-term salinity buildup. However, some locations are afflicted by acid rain, and the rainwater in such areas has an acidic pH. If this is the case, it is advised that the collected rainwater be buffered.
How to collect rainwater for aquaponics?
When it comes to collecting rainwater, there are several stages to consider. The first is the conveyance of rainfall through a drainage and piping system. Filtration and storage are the following steps.
- Catchment area: This is the location that collects rainwater. It is the initial stage of rainwater collection. A paved surface of a building, such as a roof, terrace, or courtyard, can serve as your catchment area.
- Gutters: These are the drainage pipes connected to the bottom end of a roof, where rainfall tends to collect. A sloping roof is reasonable since precipitation flows directly into the gutters. It would be best to link the gutters to your storage tanks via pipes.
- Pipes: These serve as conduits that will carry the rainwater from your catchment area to the collection units. PVC pipes are the common choice of many for their piping system.
- Initial flushing: The primary objective of first-flushing is to keep trash and contaminants out of the storage system. To achieve this, the system has a valve that ensures the first burst of water that enters the drainage system is cleansed from any form of debris.
- Filtration: This is the final step in the rainwater gathering process, and it allows you to use the water in your aquaponics. It aids in the removal of contaminants and suspended components from rainfall that has been stored. Usually, the filtration unit is consists of several layers such as sand, charcoal, and gravel.
- Storage: Depending on your demands, you might utilize a barrel or a huge water tank to store filtered rainwater. However, you should always ensure that the harvesting container is adequately covered. Small animals, insects, twigs, and dirt cannot contaminate the water if the lid is sealed correctly. Some are avoiding metal or concrete water tanks since they rust quickly.
One thing that makes aquaponics popular among food growers is its ability to use less water. Thanks to aquaponics, it is possible to cultivate both fish and plants while using 90% less water than long-established soil farming. One of the environmental issues we face today is water conservation. Through aquaponics, we can help conserve large bodies of water so that the generations after us can still enjoy them.