Fig. 6: The inner surface of the kettle after using MilliQ water following 150 boils and tap water for 100 boils.

SEM images of a new kettle, b kettle after using MilliQ water for 150 boils c kettle after using tap water for 100 boils. AFM images of d new kettle, e kettle after using MilliQ water for 150 boils and f kettle after using tap water for 100 boils.