Pool Water Treatment

Pool water treatment uses filters and regular chemical testing to keep your swimming pool free of impurities, giving you peace of mind that it is safe to swim in.

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Maintaining Pool Water Balance

With many water systems, the water used is drained away after use, however with swimming pools the water is kept within the same system to be re-used. Due to this, maintaining the chemical balance of the water in your swimming pool is essential to ensure it is kept clean and safe for users.

On the pH scale, the ideal range for a swimming pool sits between 7.2 and 7.6, with closer to 14 meaning it’s too alkaline and closer to 0 showing its too acidic. If the level of your water tips too far in either direction, it can affect the water’s hygiene and cause issues for essential pool components like the filters and pumps.

As the pH and chemical composition of a water supply varies depending on where you are in the country, there is no fixed regime for checking your pool water balance. We recommend regular pH, chlorine and alkalinity tests to ensure your pool stays within a healthy range.

Treating a Swimming Pool

To treat a swimming pool, you should start by testing the pH, chlorine and alkalinity levels of your water. The regularity of these tests can vary from daily to weekly and will depend on your water supply and the amount of use the pool is seeing.

With each of these tests, ideally your water should be sitting in the following ranges:

  • Chlorine: 1 to 3 ppm
  • Alkalinity: 80 to 120 ppm
  • pH: 7.2 to 7.6


Depending on the results, you can then use the appropriate chemicals and pH increasers or decreasers to bring your pool water within the healthy ranges. As the pH level is affected by the addition or removal of chemicals, we’d recommend testing this last and making adjustments accordingly.

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Filtering Your Swimming Pool

While chemical or ultraviolet water treatment can be used to kill bacteria and other contaminants, filters work to actually remove these particles from the swimming pool’s water supply.

Filtration systems are vital as they regularly renew the water within the system to keep it healthy and clean. By not using a filter, impurities will start to build up causing bacteria and algae to develop.

Typically 80% of water maintenance is carried out through filtration, with the further 20% covered by mechanical or chemical treatment so it’s important to choose the right filter for your pool based on its size or volume and the power of its pump.

There are different kinds of filtration systems available, such as:

  • High-rate sand filtration
  • Low-rate sand filtration
  • Cartridge filtration

Ultraviolet Light Water Treatment for Swimming Pools

By using an ultraviolet light as part of your pool water treatment you can completely break down the algae and other bacteria present.

A UV lamp can be fitted directly into a pool’s water management system so that any micro-organisms are killed as the water passes through.

While ultraviolet light is extremely effective at breaking down bacteria within the pool’s system, it cannot remove particles from the water. With this in mind, ultraviolet water treatment should be used in conjunction with filters to maintain a high level of water quality.