Rain Barrels & Rain Water Tanks: How to Use and Care for your Barrels & Tanks


No home should be without rain barrels or rainwater tanks these days. With climate change water is become a scarce resource and when you are homesteading and farming, it becomes even more apparent that when the rains fall, it is better to save it than allow it to disappear as run-off.

There are 4 types of rain barrels or rainwater tanks, each of which have their own merits; fiberglass, galvanized steel, plastic and concrete, although rain barrels can also be made of wood.

These tanks and rain barrels come in a variety of sizes and shapes and are designed to collect your rainwater efficiently which you can either use in your garden or domestic use. You could use it for drinking water too, but only if it has been sterilized and you live in an area where industrial fall-out is not a serious problem.


The average consumption of a four-person household in the city consumes about 640 liters. Therefore the size of the tank will be determined by the calculations that you make. You will need to work out how much water you will require and what sort of rainwater you can expect. Your roof area is another aspect for consideration. The meteorological department in your area will help in providing you with rainfall statistics. However, on average, you probably need a tank that can hold about 60, 000 liters.


When you collect rain water from your rain barrels or rain water tanks, you may have had the idea that you could use it for flushing toilets, washing clothes and dishes, and even drinking. You might even have thought about using it to water your garden. All of these are possible, but you cannot just use it as it is. You will need to treat the water first for drinking and domestic use.

Drinking water has to treated. When it comes off the roof it is not clean. Your roof will have dust, and leaves, small insects and debris will be trapped in the gutters. The worst problem will be that your rainwater will have faecal matter which have come from birds, lizards, rodents and other mammals, or even dead and decaying birds, reptiles and mammals.

You may also have a roof which is under trees that are poisonous and when they drop their berries and leaves these contaminate the water. The white cedar is such a tree. Besides what you can see, there are also things that you can't see. Pollutants such as industrial fall-out is always possible, and this can result in dangerous levels of lead in your system if you don't treat the water.

Less commonly, rainwater is collected in underground tanks. If these tanks are not fully sealed or protected against ground run-off, then microorganisms associated with human and animal excreta may also contaminate stored rainwater.

Any water that you collect should be filtrated. A screen should be placed at the inlet pipe where the water enters the tank to minimize the debris. The mesh one the screen should be small enough to keep mosquitoes out and it should not be made of copper or brass as they can cause a chemical reaction with the rainwater.

Despite screening, it doesn't prevent bacterial growth from forming. All water from the tank should be vigorously boiled for five minutes before being drunk which should kill any harmful bacteria.

In addition to this, the water should also be exposed to ultraviolet light irradiation to ensure that the water is free of pathogens. UV light systems require relatively low maintenance and have the advantage of not using chemicals. The UV light could be installed in pipework delivering water from a tank to a dwelling or selectively to taps used to supply water for drinking and food preparation. All of which is an important safe-guard against drinking contaminated water.


In some areas you may have to apply to your local council for planning permission to install your rainwater tank, especially the large types. It is also advisable to get a plumber or an engineer to help with the instillation to get it right, especially if you are going to install them underground.


Keeping your rainwater tanks and rain barrels clean is very important. This involves keeping the gutters and drainpipes free of leaves and debris with regular checking. It also involves checking the inlet pipe and the overflow pipes regularly making sure that they too are clean at all times. Cut away any overhanging branches of trees making sure that they are well away from your roof, whether they are poisonous or not.


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