What makes the ideal rain water harvesting tank?

Rainwater can be collected and stored in all sorts of containers, including rain barrels, drums, water tanks, underground water tanks and cisterns and even disused swimming pools. However, there are certain criteria that make for better storage vessels.

Choose the right rain water storage tank

Most rainwater harvesting is conducted via the collection of rain water off the surfaces of rooftops, directed via gutters and downpipes to a water storage container.  If good quality rainwater is to be collected and stored, the rooftop and gutters should be kept clean or a ‘first flush’ mechanism should be installed to reduce the amount of debris entering the water tank.

The water tank itself should also be of high quality and rated for storing potable water (if you ever intend drinking the rainwater, which is entirely feasible, providing it is properly filtered/purified).  Ideally, rainwater collection tanks should be made from an inert material that does not rust or corrode and does not leach chemicals into the stored water.  In many cases, a high quality polyethylene water tank with a food-grade inner lining or coating is the best choice.  A poly water tank that has been ‘roto-moulded’ (rotational moulded) is also better than plastic water tanks that have been moulded in two separate halves and joined together.  Roto-moulded plastic tanks do not have any seams and are thus less likely to crack or split (cheap poly tanks often crack along the seam – this seam can usually be clearly seen running vertically through the centre of the tank).

Next to consider is the size of the water tank.  The amount of rainwater you can harvest depends on your roof surface area and local rainfall conditions.  When the capacity of the rainwater tank has been decided upon, the shape and height of tank must be considered.  The height of the roof’s eaves and lowest gutter will determine how high the water tank can be (the water tank must be lower than the lowest point of the gutters/eaves).  This is where a ‘low profile’ version of a water tank may be better than a standard height water tank.  An example is JoJo Tanks’ standard 5000l vertical water tank which is 2100mm high versus the JoJo low profile 5000 liter water tank which is only 1660mm high and should fit under even the lowest eaves.  An added advantage of low profile water tanks is that they can more easily be hidden and they exert less downward force per square meter compared to their standard counterparts.  For small-scale, simple rainwater harvesting projects, a ‘slimline’-type tank is often desirable, for example, JoJo’s 750 litre Slimline Rainwater Tank.

Underground water tanks are another option for storing rainwater but bear in mind that pumps will be required to access the water.  Underground water tanks offer some advantages over above-ground tanks, e.g. aesthetically, they are better as they are hidden from view.  Underground water tanks are also suitable where space is at a premium.  It is important to choose underground tanks specifically designed to be buried and withstand pressure from the surrounding soil; JoJo’s rugged 6000 litre underground water tank is an example.

Click on the links below to view the wide range of JoJo water tanks suitable for rainwater storage as well as other high quality JoJo Tanks products.  JoJo vertical and horizontal water tanks are made with a food-grade, FDA-approved inner black lining that inhibits algae growth and keeps stored water fresher for longer.

JoJo Tanks South Africa offer a wide range of products such as plastic water tanks and chemical tanks to suit every household, business or agricultural need, including silo tanks and silo tank stands as well as other high quality JoJo Tanks products.  See JoJo Tanks’ VERTICAL TANKS, HORIZONTAL TANKS (transporter tanks), STEEL TANK STANDS and OTHER JOJO PRODUCTS and see JoJo Tanks’ NEW 6000 LITRE UNDERGROUND TANKS. Also see our FAQ and WATER TANK PRICES.