If you’re filling the humidifier tank with tap water, the walls of the machine will collect mineral buildup (or scale) over time. To remove scale, wipe the surface with undiluted white vinegar. “Make sure to follow the manufacturer’s cleaning guidelines, but many humidifiers can be descaled by filling the water tank with white vinegar, letting it sit for 20 minutes on the base, and then rinsing with fresh water,” advises Drake. To get into any tight crevices, use undiluted vinegar and a toothbrush to scrub away scale.
To disinfect the machine, let a solution of water and a small amount of bleach sit in the tank for 20 minutes, then rinse the machine until the smell of bleach is completely gone. Viola—your humidifier is now germ-free.