Use distilled or de-mineralized water to fill your humidifier. Distilled or de-mineralized water has less mineral content than regular tap water. Tap water contains minerals that can create deposits inside your humidifier that promote bacterial growth. And, when released into the air, these minerals often appear as white dust on your furniture. You may also breathe in some minerals that are dispersed into the air. Distilled or demineralized water has a much lower mineral content compared with tap water. In addition, use demineralization cartridges or filters if recommended by the manufacturer.
Humidor manufacturer specifically states that you cannot use tap water, use only distilled water. Tap water contains minerals that will destroy most humidification systems by leaving deposits that will clog the humidor element.