JC Pool Services Monthly January 2021




This month we talk about the conditions and give a summary of the best way to own a swimming pool and live with COVID-19.

If swimming pools are being chlorinated in accordance with current recommendations & best practices, Is this sufficient to inactivate COVID-19 virus? And should users do anything differently?


The World Health Organization states that a residual concentration of free chlorine of >0.5ppm in the pool after at least 30 minutes of contact time, at a pH of <8 is sufficient to kill Covid-19 viruses. 

Which means that, not only can chlorine act as a disinfectant, but can also tackle the virus taken into the pool by a swimmer.


UV disinfection amplifies the efficiency of chlorine based sanitizing methods, to give an extra level of protection.


Maintaining the correct level of FREE CHLORINE and the correct pH is essential to provide disinfection. 

To maximise safety:

  1. Maintain the pH between 7.2 & 7.6, ensure you are adding the required amount of Hydrochloric Acid.
  2. Ensure that the level of FREE CHLORINE is held above 0.5-1ppm at all times.
  3. To amplify the spectrum of disinfection, the use of UV is highly recommended.
  4. Continuous measurement of pH & Chlorine levels, using an analyser, is recommended, so that the users are fully informed about the water’s quality.
  5. Keep the alkalinity in check, as that will help to maintain the pH balanced.
  6. Consider using a chlorine dioxide precursor, as this will remove any biofilm build-up further reducing the chance of bacteria and virus build-up within the water.
  7. If you are treating an algal bloom, use an algaecide in conjunction with the chlorine. These products work synergistically in treating the algae and will allow the chlorine to do its job of killing off bacteria and viruses.


Adequate personal hygiene should be maintained, washing your hands with soap is the minimum, though it is recommended that the bathers shower before & after swimming. Keep the surrounding areas of the pool including showers, ladders & equipment disinfected using products specially indicated for this use.