• Phenol Red Tablets

Phenol red tablets are based on a pH sensitive dye which varies in colour between yellow at pH 6.8 and red at pH 8.4.

The Tablets Measures pH-value (6.5 - 8.4)

The optimum range for swimming pool water is pH 7.2 to 7.8.

A widely used type of test method for domestic pools is the dip cell or pooltester. This consists of a small plastic block with one or more cells into which the water sample is added. Coloured scales are provided next to each cell, showing the value of the measurement against the colour. In addition to pH, these are often used, with the correct tablet, to measure chlorine, bromine and alkalinity.