I purchased a 1 gallon cool mist humidifier about 2 months ago and it has since emitted a white powder residue all over the entire room that it operates in. Can you tell me what causes this and what to do to correct it. If it is something harmful we need to discontinue using it. I have the 2 gallon humidifier in my daughters room (for almost 2 years) with no problems

Thank you, Leaha

Humidifiers - Vicks - V4500 1 Gallon Humidifier