[csours]

We used Ultrasonic humidifiers in a server room (to cut down on static risk) and I can confirm they get covered in minerals

[superseeplus]

Amazon reviews on ultrasonic humidifiers complained that their expensive home electronics died because of the dust.

[csours]

Hah, well I don't work there anymore. They did have reverse osmosis water filters on them, but no air filters.

[falcolas]

Turn them down (ideally to the point where you can barely see the mist). They don't have to run at full blast to be effective.