Tips for choosing the right home water consumption system

There are many types of home water consumption systems available and they each have certain advantages and disadvantages. The following list should help you determine which type would be best suited to your needs.

Advantages:

• large capacity;
• can be installed underground or under buildings;
• long-lasting;
• keeps light out

Disadvantages:

• expensive;
• excavation required to install underground;
• can crack

Advantages:

• economical;
• light;
• resistant to high temperatures and corrosion

Disadvantages:

• fragile, prone to cracking;
• may let light in;
• some types not suitable for drinking water

Advantages:

• economical;
• light;
• UV-resistant;
• huge range of shapes, colours, sizes and capacities

Disadvantages:

• longevity depends on level of UV treatment;
• can be an eyesore

Advantages:

• economical;
• reasonably light;
• range of sizes and shapes

Disadvantages:

• limited life span;
• prone to rust;
• can be an eyesore

• Use your tank water regularly. This will make your investment worthwhile and ensure that the water doesn't stagnate.
• Drain and clean the tank at least once every two years.
• If you don't have gutter shields or covers, regularly cut back trees and bushes that overhang the roof.
• Check that the covers on top of your tank and any other openings fit snugly. Any light that enters the tank will encourage algae to grow.
• Make sure rainwater does not flow into your main supply.
• Do not drink the water from the tank unless it has been purified.

Take some time to work out where you want to use rainwater and how much you need. Also, look into local rainfall patterns. If most of the rain in your area falls in one season, then it is likely that your tank won't cover your garden watering needs in the dry months. In a domestic situation, a tank with a 2,000 to 5,000 L(528 to 1320 gal) capacity should suffice.

• First, work out how much rain you could collect. Every mL of rain on a square metre of roof provides one L (four cups) of water. So, to calculate your total potential capacity, multiply the area of your roof (in square metres) by the local annual rainfall (in mL).
• Work out how much water you want to collect by using the water usage figures below.
• Evaluate how much you will need of the total water you could collect from your roof – you probably won't be able to, or want to, catch it all.
• Now you are ready to choose your tank. Make sure you choose one that suits your budget and remember to factor in costs for delivery, installation and any accessories you will require.

Toilet

• Non-efficient full flush 11 litres
• Non-efficient half flush 5.5 litres
• Efficient full flush 6 litres
• Efficient half flush 3 litres

Shower

• Non-efficient showerhead up to 23 litres a minute
• Efficient shower-head 9 litres a minute

Bath

• Low bath50 litres
• Full bath150 litres

Dishwashing

• By hand18 litres
• Non-efficient machine 36 litres
• Efficient machine16 litres

Clothes washing

• Non-efficient top-loader up to 240 litres

• Efficient top-loader110 litres
• Efficient front-loader100 litres

General use

• Washing, brushing teeth, etc.18 litres per person per day
• Garden sprinkler1,000 litres an hour
• Washing car with hose17 litres a minute