Water Hardness Test Kit

This kit measures the calcium carbonate & magnesium carbonate that is in your water, which is what precipitates when water is heated and adheres to the inside of the boiler and pipework in espresso machines.

This measure is also known as carbonate hardness and for our purposes is equivalent to alkalinity

The kit is very easy to use; follow the simple instructions on the adhesive label on the box that the test kit is supplied in

Shake the bottle of reagent to ensure no settling has occured

Add one drop of reagent to the 20mL water sample in the test bottle

Screw top on test bottle after each drop is added and shake, then sit the bottle on the bench and observe the colour under strong light

When the change occurs the solution will dramatically shift from a shade of pink to a shade of blue - there is no ambiguity

Carefully keep count of the number of drops of reagent you have added

When the colour change is observed multiply the number of drops of reagent that you have added by 10 to calculate the total temporary hardness in ppm (as CaCO3)

For reference Volvic water has a temporary hardness around 85mg/L and even then scale will very slowly form in the boiler, as silicates

Ideally you do not want the total temporary hardness value to exceed 70mg/L