Answer:
Hikaru features an intelligent cleaning reminder: after every 200 cups brewed, the cleaning indicator will light up to remind you to descale the water tank. You can follow the instructions in the manual or app descaling guide to activate the descaling mode for cleaning.
We recommend using filtered or purified water to minimize scale buildup. If your local water is high in minerals, descale the water tank more frequently to maintain heating efficiency and stable water flow.
(See User Manual pp.12-13)

