Why Does My Swimming Pool pH Matter?


From broken filters to itchy eyes, the wrong pH in your swimming pool can cause a tide of problems. Thankfully, you don’t need a degree in chemistry to maintain the right pH levels in your indoor or outdoor pool. Here’s a quick guide to getting pH right.


What Is pH?

In chemistry, the potential of hydrogen (pH) is a mathematical equation used to describe the acidity or alkalinity of a liquid. The pH scale runs from 0 to 14. Acids have a low pH, and alkalines have a high pH. For instance, sulphuric acid has a pH of 1, and sodium hydroxide has a pH of 14. Nobody would survive taking a dip in either of them, which is one of the reasons why swimming pools require a more neutral pH of 7.4.


The Relationship Between pH and Chlorine

Chlorine is a disinfectant that keeps swimmers safe by controlling bacteria and algae. The pH of the water makes a difference to how well chlorine can do its job. A pH of 6.0 makes chlorine far too effective, so that while it is eradicating bacteria, it stings and burns swimmers too. A pH of 8.0 makes chlorine virtually pointless, with only 3% effectiveness that allows bacteria to flourish. A pH of 7.4 enables chlorine to do its job perfectly, safely, and comfortably.


What Are The Signs That Pool pH Is Too High or Too Low?

There are very clear signs when the pH is off. When it is too low, there is usually corrosion of the heating elements, the pump, and any other metal components. These often leave a reddish stain as the acid dissolves them. If the pH is too high, the water becomes cloudy, and grey-coloured scales start to form on the walls and surfaces. Over time, filters and heaters start to become clogged and inefficient, until they eventually break.


What Affects pH?

Lots of different factors can affect pool pH. These include sanitisers, algaecides, and filter acids, as well as the general factors that influence water balance such as frequency of use, leaves and debris, and rainwater. The water hardness is also influential. Hard water areas – where water forms limescale due to soluble chalk content – have a higher pH that causes scaling and clouding. Soft water has a lower pH that can quickly cause metal corrosion.


How Difficult Is It To Maintain a pH of 7.4?

Swimming pool pH is affected and controlled by Total Alkalinity (TA). This is very easy to test for by using Litmus strips, liquid reagents, and test tablets. If the pH is not correct, it is then a case of diagnosing the problem and correcting the water balance as required. Some home pool owners find this straightforward, but – as pool chemistry can be highly complex – most people prefer to ask a specialist to help. Professionals can help to establish a simple, easy-to-follow care routine that reduces the risk of the pH becoming unstable, enabling everyone to enjoy the water while avoiding expensive damage to critical components.


If your water is cloudy, or your metal is showing signs of corrosion, don’t wait until you need expensive repairs! At JB Elite Services, our specialists can diagnose and treat pH problems swiftly, so pick up the phone today.

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