A swimming pool seems a great idea when you’re thinking of relocating to warmer climes. It certainly was for us when we thought of moving to Spain.

A villa with a swimming pool seems to be high on the wish list of most people coming here. The thought of owning your own pool conjures images of glamour, especially after watching all those glittering movies and seeing the lifestyle that movie stars enjoy – most of us hanker for a chunk for ourselves – and why not.

Being a proud possessor of your own swimming pool isn’t all hearts and roses though. The first thing you have to learn is how to actually handle it. If you’re not prepared to put in a little work, forget it.

The chemical balance needs to be carefully controlled on a regular basis to avoid bacterial growth and algae formation. The last thing you or your visitors want is to catch something nasty after taking a leisurely dip. At the very least, the level of pH and chlorine has to be maintained. Tablets are available to adjust both. Some tablets are multifunctional and add an anti-algae component, and possibly a flocculent to keep the water at its Sunday best.

But how often are you able to use the swimming pool?

Most people are under the impression they’ll be swimming for most of the year - rubbish. An outdoor swimming pool is only useful for about four months of the year –yet still needs to be maintained…. Ouch!

I’m not one for wasting energy, time, or money, and for me, not using the pool is a waste. I search for ways to improve – and improve I do. First on the list of enhancements is a swimming pool cover…. Wow – great improvement.

Heat heat heat.

A blue translucent bubble-wrap cover allows energy from the sun to heat the swimming pool, acting like an enormous solar panel. The swimming pool cover also insulates the pool and keeps the heat in at night: a win-win situation - heats the swimming pool during the day, keeps the heat in at night – what more could you ask? An unprotected swimming pool can loose up to 3 degrees Celsius overnight. With a swimming pool cover, the heat loss is reduced to 1 degree Celsius or less.

A swimming pool cover not only heats and insulates, it protects pool water from evaporation. Evaporation is evil. It wastes the precious resource and in doing so removes heat from the pool - bad. Wet your finger on a windy day and see how much colder it feels.

With the combined effects of heat input, insulation and protection from evaporation, the temperature of a covered pool can be more than 8 degrees Celsius higher than a similar uncovered swimming pool.

The benefits of a swimming pool cover doesn’t end there. Dust and leaves collect on the swimming pool cover instead of in the pool – and can be washed off in a safe area – so reducing debris problems in the swimming pool. Not only that, but chemical consumption is greatly reduced, a great environmental benefit. Overall, having a swimming pool cover makes a lot of sense and should be treated as number one priority on the list of pool improvements.

Pool temperatures can be further improved by adding external solar heating panels. The only problem is capital expense. A homemade device can be installed at a much lower cost.

I installed 180 metres of 15mm copper tubing formed into a zigzag matrix, painted matt black to give maximum thermal transfer, covered it with transparent roof plastic to avoid heat loss to surrounding air, and added a water pump. The pool pump delivers 60 litres of water per minute, and the exit temperature of the water from the system on a warm sunny day is at least 1 degree Celsius higher than the input.

Amount of heat transferred = mass x change in temperature x specific heat

q = m(DT)Cp

Where:- q= quantity of heat m= mass DT = change in temperature Cp= Specific Heat

In SI units we should use grams, metres and seconds.

The volume of water per second is 1 litre, which has a mass of 1000 g. The specific heat of water = 4.186 per gram Change in temp = 1C

Therefore q = 1000 x 1 x 4.186= 4186 joules

A joule is defined as 1 watt of energy dissipated over 1 second. We’re dealing in seconds, therefore the heat energy is equivalent to 4186 watt

In excess of 4kW of heat continuously added to the swimming pool – a nice little bonus - leave that on for 6 hours a day and it makes a difference. With a swimming pool cover and a homemade solar heat system, the swimming period can be extended by three or four weeks at the start of the season and a similar period at the end – a nice little extension. What more could you wish for…

... Now what inexpensive mod can I do next?