PH stands for Potential Hydrogen’s and is a measurement of the positive Hydrogen’s (+H) and negative Hydroxides (-OH) within the water.

Enough of the waffle, pH is, however, one of the most important areas of pool water chemistry.

It has a very strong bearing on the overall balance of the pool water. If the pH is high it is more likely to cause scale to form on the pool interior and on the inside of the pipework, filter and heater.

(A thousand of an inch of scale on the inside of your heater reduces the heaters efficiency by 50%)

If the pH is low, the pool water is more likely to be corrosive, taking the plasticiser out of the liner

(pre-ageing the material) or grout out from between the tiles. As most pool heaters have to be

made with good heat conductivity in mind, the metals used tend to be soft metals and these are

very susceptible to attack and pool water with a low pH will eat the inside of your heater, causing expensive damage.

The pH also determines how efficient your chlorine is. The higher the pH the less effective the chlorine is, and the difference is considerable. Chlorine in pool water with a pH of between 7.8 and

8.0 is 50% less effective than that in pool water with a pH of 7.4!