J.W.Green Swimming Pools Ltd.

Turning your dreams into reality.


If you have a question that isn’t answered in the below information please contact us we’re happy to help.

On site swimming pool guides & tutorials  …

Opening your swimming pool.

Testing for chlorine

Choosing a pool cover

Pool heating systems

What to do if your pool turns green

Winter poolside safety guide

Buying a house with a pool?


What is the most popular size for a domestic outdoor swimming pool?
5 metres x 10 metres, with a constant water depth of 1.2 metres and a free board of 150mm above water line. No diving.

What is the most popular size for a domestic indoor swimming pool?
4.6 metres  x 9.2 metres, again with a constant depth of 1.2 metres. No diving

Why shouldn’t I build in a conservatory type structure?
This is purely my own view, hundreds of people have swimming pools in fixed conservatories, slide open units and other variations on the theme.In my opinion, you will cook in the summer and freeze in the winter. Much better to have a conventional well insulated building with minimum regulation u values. A conservatory or a conventional type building will require a well designed  heating  / air conditioning control system to keep the room at least one or two degrees above the temperature of the swimming pool. With the latter, so long as maximum insulation has been designed in over and above minimum regulations, running costs will be more economical. In Scandinavia the trend  is towards tripple glazing, which is said to be helping minimize the cost on total environmental control.

Why do you suggest a thermal cover on an indoor swimming pool?
With a cover in place and a well designed air handling system  (AHU), once the pool hall has dried out, the AHU hygrometer can turn the unit off and make big savings on energy. Whilst with a swimming pool run one or two degrees lower than the hall temperature, there will be little evaporation and less humidity for the AHU to control. Cover in place, room temperature can drop and there will be little creep of humidity into the pool hall. If your pool is only used on average two to three hours a day, big savings can be made on energy.
There is also a liquid thermal blanket on the market. Used widely on both commercial and domestic swimming pools, indoor and outdoor. Useful where a conventional cover is not practical. e.g. on freeform shaped swimming pools.
For domestic swimming pools a manually  dosed pack is available. An automatic dosing system is available for any size swimming pool.

Can I use anything other than chlorine or bromine for my swimming pool or spa?
Yes there is a wide range of optional systems, though with many there is still a requirement for a small chlorine residual. ptions include Ozone, Ultra Violet, Ionisers and alternative oxidiser systems – no smell, no taste, manual or automatic systems.

Is a thermal cover a safety cover?
NO!  A thermal cover is only intended to help lock in heat to the water  and not act as a safety cover. There are several thermal covers on the market that CAN double as a safety cover. These include a plastic slatted cover, similar to a roller shutter door. This cover floats on the swimming pool, but MUST have specialist handrail fitted or a ledge designed into the perimeter to support the cover should someone fall on it. Another option is a cover with a cable set into the edges. The cable sits in a track either on the pool surround or set in a track in the wall of the swimming pool. The cable drags the cover on and off the swimming pool via pullies set into the surround

What can I put in my swimming pool once, to keep it clear all year?
Nothing, a swimming pool will require regular testing and dosing either manually or via an automatic dosing system.

What are the options for heating my swimming pool?
Oil, natural gas, bottled gas, heat pump – air to water or ground to water, electric heater, solar heating (solar systems will not provide enough energy to provide heating all year in the UK).

Why did the last owner tell me not to empty the swimming pool?
There may be a high water table. If so a swimming pool would be like a boat. With water in the ground and an empty swimming pool, there is a strong possibility the pool could try to float out of the ground.
If it is a panel type liner pool or a GRP  pool it is possible the ground pressure could push in on the walls and distort the shape. Better to pump out the ground water prior to emptying the swimming pool and to control the ground water for all of the time the pool it empty. Always bring in a good pool company before trying to empty.

Can I convert my liner swimming pool to a mosaic finish swimming pool?
If the shell is a blockwork shell then it may be possible. The walls would need to be meshed and the floor would have to be set with reinforced concrete, dowelled into the walls, followed by a total specialist render coat or coats. A mosaic pool must be monolithic to prevent any movement. A liner is less demanding and will stretch with any slight movement. With a panel pool forget it. Best build a new pool shell within the existing, unless this would make the new shell too small.

I’m vacuuming my swimming pool through the filter, but is is now very cloudy what is going on?
Dead algae or other contaminants may be too fine for some filter media to take out. Best vacuum such material to waste. Ask your pool pro.

There is a line of sand on the floor in line with the inlet spreaders?
It is probable that the laterals have become brittle with age and one is broken, thus allowing filter media to escape to the swimming pool.

With a good swimming pool system installed, how much time will I need to spend on my swimming pool a week to keep it in tip top condition?
With a domestic swimming pool, if you are spending more than one hour a week looking after yitl, you are probably doing something wrong or have never been trained properly what to do. Give us a call and we can send an engineer to go through the various operations and water testing and dosing with you.

If you have a question you’d like answered that isn’t listed above let us know.

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