How do I measure and set the water hardness?

Immerse the included Total Hardness Test indicator paper (D1) completely in a glass of water for one second, remove and shake lightly, then wait about a minute — 1 to 4 red squares will form indicating the hardness level. To set it on the machine, go to the settings menu, press 'WATER HARDNESS', and select the corresponding level (Level 1 = soft, Level 4 = very hard). The machine defaults to hardness level 4, and setting it correctly means descaling reminders will appear less frequently for softer water. (Page 19)