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water management
rain water storage and collection
poly water tanks
Polyethylene tanks, commonly  called poly or plastic tanks, are the most widespread water tanks in use in Australia today.  This page looks at their relative advantages and disadvantages when compared to other types of water tanks. 

  • Photo of a poly water tank
    One of two 13,500 Litre (3,000 gallon) poly water tanks in my garden.  It has a trellis surrounding it on three sides to support Chinese gooseberry and Scarlet Runner bean plants.
    Lighter than all other types of water tanks, which makes them simpler to move.
  • Easier to install than galvanised water tanks as they can just be set on a sand base while galvanised tanks need a heavy duty stand.
  • Because they are moulded they come in a large range of different shapes, not just round ones, making them more suitable for tight spots such as between the side of a house and a fence.
  • Cheaper than galvanised iron or concrete water tanks of similar size. The only tanks that are cheaper (per litre of storage capacity) are very large poured concrete tanks, but these large tanks are usually not suitable for urban backyards.
  • They can be buried up to one third of their height into the ground, which is a real advantage if you need to get the top of your tank to sit under the roof line at a point where the ground slopes steeply up.  There are also specialist poly tanks that can be buried entirely underground.

  • Poly tanks have only been on the market for less than twenty five years and it is unknown how they will break down when they are very old.  They may well be quite an environmental problem when it comes to disposing them after their useful lifespan has passed.

I have two 13,500 litre poly water tanks which are the main water supply for the garden.  They are also connected to the toilet and laundry during the Winter months plus there is an  all year round connection to the kitchen to supply drinking  water through a filtered tap.