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Do Aquaponics Systems Save Water?
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According to the United States Geological Survey, 70% of freshwater withdrawals in the world were consumed for irrigation. Due to this many drought-stricken countries reassess their water consumption practices by reallocating some of the water used agriculture to other needy sectors. Countries are not alone, in fact, the World Bank believes that re-allocation of water is necessary to facilitate urbanization and industrialization. This critical issue in water usage is one of the reasons why many growers are turning to aquaponics as a way to reduce water costs and unnecessary waste. But does aquaponics save water? Can the system actually reduce water costs for your garden?
Yes, studies have shown that aquaponics uses 90% less water than traditional farming. Unlike soil that quickly absorbs water, especially in warmer seasons, water used for aquaponics is continuously recirculated from the fish tanks to the plant beds. In the process, the water is also filtered by the plant beds, thus providing a water-efficient solution.
In this article, we will discuss how aquaponic systems help conserve water by focusing on the process of recirculation. We will also discuss an alternative method for collecting water for use in your system.
How do aquaponic systems save water?
One of the critical components of aquaponics is water. It helps facilitate plant growth by carrying necessary nutrients from the fish waste to the grow beds. In setting up the system, the initial water requirements for aquaponics are quite large, but through the process of recirculation, it consumes less water than in soil gardening in the long run. Aside from this, there is also minimal water loss, so growers only have to add a little amount of water every week.
A research study conducted by the University of Gothenburg concluded that the process of recirculation in an aquaponic unit achieves 95% to 99% of water re-use efficiency. The water quality is maintained in the system despite the continuous usage, and it only required less than 100-liter per 1 kilogram of fish.
This result is also similar to the claim of Ouroboros Farm, in which they found that despite having a sizable aquaponic farm, they only used 60,000 gallons of water a year due to recirculation. As compared to a soil garden that can absorb more than 100 gallons a day depending on size, aquaponics is proving to be a reliable planting technique that can substantially reduce water usage in agricultural activities.
Water loss in aquaponics explained
Despite being more efficient in water usage, an aquaponic system also experiences water loss because of natural factors and set-up malfunctions. The good news is, the amount of water loss in this soilless method can be minimal.
In another study about energy and water use of a small-scale raft aquaponics system, the results showed that a non-commercial unit only experiences 1% water loss every day and uses an average of 35,950 liters for top-off every year. The recorded water loss was due to evapotranspiration and leaks.
Minimizing water loss in aquaponics
Evapotranspiration is the natural evaporation of water through the plants, and this cannot be prevented because it is essential for crop growth. Leaks, on the other hand, are very preventable through careful monitoring. Below are some different ways to minimize water loss in aquaponics.
- Use float switches to control the water pump and prevent it from expelling all the water out of the system. Once the target water level on the sump tank is achieved, the float switch will automatically turn off to avoid a large amount of water loss.
- Maintain the correct temperature for your crops so they won’t use a significant amount of water in evapotranspiration.
- There are instances where wild animals can displace or break water pipes, so it is suggested to install a fence to prevent them from creating damages.
Rainwater as an alternative aquaponic water source
Another reason why aquaponics saves a lot of water and running costs every year is because of its water sources. The most suggested among all these is rainwater because it is free, and it usually doesn’t contain toxins that are harmful to both fish and plants.
However, believe it or not, capturing rainwater in some cities is deemed illegal due to the potential of insects breeding in the water and spreading disease. If you decide to capture rainwater, be sure to check your local government regulations before getting started.
Rainwater harvesting techniques
Now that you know the benefits of rainwater to plant growth and water conservation, here are three techniques on rainwater harvesting that you might find useful in saving water for your aquaponic garden:
Rooftop rainwater harvesting
Rooftop harvesting is the most common system in collecting rainwater. This method is done by using a large container and connecting it to drainage pipes around your house or building. The water that is harvested through this technique will be enough to fill small scale aquaponic units.
Rain harvesting saucers
If you want to be a little bit creative and your goal is only to collect water for your aquaponic unit’s weekly top-offs, you can try making rain harvesting saucers. This rainwater harvesting tool also maintains the correct pH level of the water needed by your plants.
Surface runoff rainwater harvesting
This technique is also known as recharging groundwater aquifers and is another good way to catch and save water for your system. Through this system, rainwater is accumulated in wells, trenches, and pits and infiltrated.
Conclusion: Does aquaponics save water?
When it comes to water consumption, an aquaponics garden uses less water than traditional ones because of its recirculation capabilities. Unlike plants in soil that absorb water in just a short time, aquaponic crops can thrive using the same water for several weeks. This method is highly sustainable since water loss is also minimal and can also be prevented, given the consistent maintenance of the system. Aside from this, the possibility of using rainwater to fill your tanks does not only helps conserve water but also lower your running costs each year.