All about pH on pool / spa water

The pH or hydrogen potential is a key indicator of water quality that measures the acidity of the water and contributes to its balance. The pH is strongly linked to the quality of the disinfection, for example going from pH 7.2 to pH 7.6 reduces the efficiency of the chlorine disinfection by 22%.

What is the pH used for?

Our chemistry expert explains in video all you need to know about pH for your pool or spa.

What is pH? A chemist tells you everything in video to better control the water of your pool or spa.

What is the ideal pH level for swimming?

Ideally the water in your pool or spa should be between 7 and 7.4 . This is the optimum value for disinfecting your water. However, this depends very much on the products you use or the region you live in. As long as the pH of your water is between 5 and 9 there is no health risk, but the pH should be monitored continuously because it influences the other parameters of the water balance.

  • The pH is below 7: use pH + tablets to balance the water
  • pH is up to 7: use pH – tablets to balance the water

The pH does not change after adding pH - or pH+? 

If the pH of the water does not change after adding pH - or +, this may mean that your water is buffered: the alkalinity level is too high.

  • For your pool : add liquid pH- not pH-paste, and then activate continuous filtration to lower the TAC and change the pH.
  • For your spa: activate the jets continuously to release the minerals in the form of gas.

Check your ICO's pH probe measurements

ICO measures pH, ORP and TDS hourly. To check the measurements of your ICO's pH sensor, you can perform the mineral water test at home very simply. See the video to perform the mineral water test.

The mineral water test is perfect for testing pH measuring instruments. Video tutorial on the Ondilo Youtube channel