Cheaper distilled water??

[Piper]

I've never had a problem using tap water in my humidifier, but every water source is different.

McJulie

[Diane]

I use an ultrasonic humidifier, and the process does put a lot of particulate in the air. Not, sticky or water spots type stuff, but a fine white dust. If you use distilled water this does not happen. If you are using a heat based humidifier, this is not a problem as the particulates settle in the water (that white/brown crust in the container.)

[jtlqh]

The heated one could add a lot of money on your electric bill. The cool/mist one that uses filter does not send out the minerals (got traped in the filter), but the filter could cost a lot, and you will need to change the filter every 6 months. I guess there is no cheap ways to add humidity.