Choosing a rainwater tank

Investing in a rainwater tank means you'll reduce your water bill and help preserve one of our most precious resources. 

To guide you in choosing a tank that best suits your situation, we've put together some points for you to consider.

Tank size and rainfall

The first decision you'll need to make when purchasing a tank is the size. Ask yourself these questions to help you pick the right one:

  • How often will I be using the rainwater held in my tank?
  • How much rain does the area I live in typically receive?
  • How much space do I have around my home for a tank?
  • Will my tank require any structural support?

Tank material

The type of material you select for your tank will depend on its specific purpose.


These tanks come with corrosive resistant coatings to prevent rust. There should be at least two metres of plastic pipe between a steel tank and copper, brass or bronze fittings as they can cause corrosion. Galvanised and Zincalume steel can be considered as an alternative, however they are both prone to rusting. Copper and stainless steel can also be considered for specific situations.


Fibreglass tanks are durable and resist corrosion. However, they are often more expensive and can expose the stored water to sunlight. Stagnant water exposed to sunlight can allow algae to grow, some forms of which may be toxic for both humans and pets. Ensure you purchase a tank that is manufactured with sufficient pigment to prevent light entering the tank.


These tanks are strong and heavy, which means they can be installed underground. New concrete tanks may need to be flushed clean because they can release excess lime, leading to a high pH in the water. Some concrete tanks require a lining to be installed.


Plastic tanks respond well to bumps and are non-corrosive. These are often the cheapest tanks. Their advantage is that they are lightweight, easy to transport and available in a range of colours.