DescriptionA 5ml. sample of water to be tested is placed in the plastic vessel supplied. Drops of the test reagent are added until the color of the sample turns pink and then blue.Each drop added until there is the color change to blue equals to 1French Degree of Hardness (for example 19 drops added till the sample turns blue means that the water tested has a hardness of 19 French Degrees).Conversion for water hardness is as follows: 1 ppm=1 mg/L=0.1 French=0.0556 Deutch=0.07 English
