There are a number of water storage tanks that can be used for harvesting rainwater. Once we understand the advantages and disadvantages of the different styles of water storage tanks we will be able to decide which one is best for our use.
Polyethylene rain water storage tanks are one of the most popular for collecting rainwater. The polyethylene tank has the most advantages and that is why they are so popular. They not only can be place above ground but can also be used as underground rain water tanks. These water storage tanks are less expensive than some of the other types; they are light weight, easily carried, and are resistant to UV rays.
The fiberglass water storage tank is also very popular. Their biggest advantage is a resistance to chemical corrosion and rust. The fiberglass tank is also able to tolerate extreme weather conditions. Fiberglass rainwater collection tanks are very popular due to these advantages but they are more expensive to purchase.
Metal water storage tanks are constructed of stainless, steel, or copper and can be coated with a color polymer. These tanks will last a long time and generally are rust proof. Another big advantage to these metal tanks is they also hold up during extreme weather conditions. Another type of water storage tank is constructed of concrete but carries a couple of disadvantages. They have a tendency to crack over time and you will have to drain the tank to repair it. Another disadvantage is it attracts algae in the sunlight.
In order to harvest rainwater you will need rain gutters attached to your roof. A downspout diverter will also be needed so that the rainwater will go directly to your water storage tank. A debris screen should be installed on the rain barrel in order to filter out pine needles, tree leaves, and other types of debris that can come from your roof. If a screen is not used all the debris will collect in the bottom of storage tank and clog your outflow. You can use a wire mesh screen placed at the end of your downspout or you can place one on the storage tank itself. Placing it on the end of a downspout will require a little maintenance periodically to remove the debris. The lid on your water storage tank should be fitted properly to protect children from getting in or falling in. A tight lid will also prevent mosquitoes from breeding in your rainwater.
You can install a standard water spigot near the bottom of the tank or you can use an on/off valve on a length of hose so gravity can do the rest of the job. A longer hose can also be used if your garden is close enough to the water storage tank or just reach inside the tank and fill up a watering can.
Rainwater harvesting is a big part of life in many sections of the world for the garden and also household use. If your home has a 1,300 square foot roof, and you receive about ten inches of rainwater a year you can harvest over eight thousand gallons in a year. That is a lot of free water that can be used even if you are in a drought.