Harvesting rain water for Hydroponics in South Africa
Water can be expensive to use for your hydroponic system if you are making use of a reverse osmosis system.
Rainwater harvesting is an excellent way to maximize water efficiency. Rather than letting the water to simply enter the drainage system, rainwater harvesting lets you store the water and utilize it for multiple functions in home and the garden. To use rainwater in your home, you need filtration and pumping system but to use in garden you can use simple set-up.
By harvesting the rainwater that falls on your property and reusing household water you can collect sufficient free water to meet the water requirements of your garden.
Harvesting rainwater works well in regions which have heavy rainfall or prolonged rainy periods, both of which result in water run-off. If you utilise all the principles of water wise gardening, rainwater can provide nearly all the water needed by your garden. What a saving on your water bill! When the rainy season ends, and the rain tanks finally run empty, then grey water can be used to water areas such as lawns, trees and shrubs.
Collecting rainwater from the roof is the most efficient means of harvesting water. Did you know that every 1m² of roof will generate 1 litre of water from 1mm of rainfall? Put differently, if you receive South Africa’s average annual rainfall (464mm) you can harvest 464 litres (0.4 kilolitres) of free water per year per 1m² of roof – enough water for 2 showers.
To find out how much rainwater in litres can be harvested from your roof per year multiply the area of your roof in m² (or the area of your house) by the amount of rainfall your area received per year in mm. Allow for 15% wastage. To change this figure to kilolitres, divide by 100. Deduct this amount from your annual electricity bill to see how much you will save on water bills for the year.
Rather than letting this free water run away from your property, use it by directing the water to where you want it, or by storing it in a water tank for later use in the garden.