Why does the pH increase?

• The pH of the water can rise due to the use of alkaline products such as bleach (sodium hypochlorite), calcium hypochlorite, but also the hydrogen produced by the salt chlorinator.
• If your pool is equipped with an overflow system, a waterfall, or even a counter-current swimming system, the resulting eddies will cause carbon dioxide to evaporate, which in turn naturally increases the pH.
• In some regions, the local water supply can also tend to increase the pH.

Why does the pH drop?

• The use of acidic products: some stabilised chlorines will reduce the water's pH.
• Acid rain has a pH between 2.5 and 4 which causes a drop in the pool water's pH.
• The pH can vary greatly if your pool is equipped with an automatic system that is poorly calibrated (dosing and/or regulating pump).
• If the alkalinity level (TAC) is too low, this will have the effect of lowering the pH (to find out more about the TAC, follow this link).

• To increase the pool's pH: Use hth®  pH PLUS POWDER to increase the pH between 7.0 et 7.4 (in front of the discharge nozzles, filtration operating).  

• To lower the pool's pH: Lower the pH to 7.0 with hth®  pH MINUS MICRO-BALLS (in front of the discharge nozzles, filtration operating) and maintain this level for several days.

   Did you know?

Each level on the pH measurement scale is ten times higher than the previous one.

For example, water with a pH of 6 is ten times more acidic than water with a pH of 7.