A:AnswerThis is a "personal" humidifier not a room humidifier. Great for a desk space or beside a bed. It expells 16 oz of water over 9 hours. Use distilled or water with minimal total dissolved solids (TDS). It is easy to clean the spray mechanism with a qtip and vinegar. I have never experienced the white mist residue normally associated with ultrasonic humidifiers because I use bottled water wirh a low TDS.
