[DesertTwang]

I never had issues with white deposits as others have reported, despite using very hard tap water in our mister. That said, we chose one that comes with a built-in filter, so perhaps that's the key. Using distilled water in a humidifier is cost-prohibitive in my experience. You'd spend hundreds of dollars a year, and it'd be much cheaper in the long run to install a whole-house humidification system. On the downside, I never noticed a significant impact on humidity. I still don't understand why that is, but in my experience, evaporative humidifiers work great in increasing relative humidity in a room, while misters look much more impressive as they spew visible droplets into the air, but the hygrometers don't register any added moisture for some reason.