Single use water hardness test strip to test water quality for your espresso machine or coffee maker. The test strip comes with a key for reference of different water hardness levels. The preferred hardness level for espresso machines and coffee makers is at about 50 ppm or 3 grains per gallon.
Water quality from city water and well water changes seasonally and bottled water doesn't remain at a constant hardness level from bottle to bottle. We recommend using test strips often to maintain a clean espresso machine and coffee maker.