A solar pool heater enables you and your family to enjoy your swimming pool or outdoor spa for a greater part of the year. Into spring and autumn. And into cooler mornings and evenings. When others are shivering!

There are four ways to heat your pool

Electric heater

Gas, usually a propane heater

Using a pool cover

Solar pool heater

The solar solution is best. It's cheap to run and you don't contribute to greenhouse gas emissions. A guilt-free time in your comfortably warm pool or outdoor spa! Why not.

A commercial pool heater can cost you up to 00. But you can build your own at a small fraction of that cost.

Just look around on the web for guides that give you clear instructions of how to build your system. There are several.

Be sure to look for these essential elements at least, in any guide you buy:

A clear list of materials with step-by-step instructions

Materials should be easy to source locally and be inexpensive

No requirements for complicated engineering, electrical skills or welding

Clear diagrams

Some troubleshooting suggestions

How do solar pool heaters work?

They run on a passive solar principle.

Simply, pool water runs through long lengths of flexible tubing. These are suspended in front of reflectors to receive and transmit the sun's warmth to the water in the tubing. The tubing should be protected, say with with polythene sheeting, from any wind chill.

The reflectors can be made out of halved storm water piping, sprayed with chrome paint to maximise their reflective powers. To circulate this warmed water through your pool or spa you will need a small pond pump or solar electric pump. The latter is more expensive, but obviously you will help the environment and your wallet by spending a little more to start with.

One guide suggests that minimum pump specifications should be that it delivers 10 litres per minute (120 gals/hour) and is capable of raising water to 1.6m (5