Shows the alkalinity or acidity of the water. It is generally a good idea to keep it at about 7 (neutral pH).
If it is less than 7: the water is acid and attacks the skin and the pool lining,
If it exceeds 7.4: it may be uncomfortable for bathers (making the eyes smart), it favours the development of algae and calcium deposits, it hinders the effectiveness of the flocculant, etc.
This is the hardness of the water which corresponds to its calcium and magnesium content.
If the value exceeds 25°, we recommend adding a calcium carbonate sequestrant once during the season (e.g.: BIO-UV ANTI-CALCAIRE).
Very hard water causes scale deposits that damages piping.
Water that is too soft (acid) may be corrosive.
This is the bicarbonate and carbonate content of the water, i.e. its alkalinity.
It should be between 10 and 15°, and can be changed using suitable products (TAC+ or TAC-).