Water balance: pH and Total Alkalinity

Potential of hydrogen, or pH, is a measure of the acidity or alkalinity of a substance. Your spa water should have a pH between 7.2 and 7.6.

A low pH can cause skin irritation and discomfort, and in the long term it may even lead to corrosion of the spa equipment. A high pH will reduce the effectiveness of your disinfectant (particularly if you use a chlorine-based product), and can lead to calcium deposits on walls and pipework.