How do I measure and set the water hardness?

Fill a glass with water, immerse the test strip supplied with the appliance, and read the water hardness after one minute by counting the number of red zones. Set the appliance to the corresponding hardness level between 0 (very soft, less than 3° dH) and 4 (very hard, more than 21° dH). You can update this setting via PROG – Settings – Water hardness. (Page 6)