Usage Information: Use sterile distilled water whenever possible to reduce the possibility of contamination and scaling. If using distilled water, remove the humidifier bottle every 7 days, wash with mild soap and water and rinse thoroughly. If using boiled tap water, remove the humidifier bottle every 3 days, wash with mild soap and water, rinse thoroughly, and allow to air dry. If the humidifier shows scaling, damage or wear and tear, replace immediately. For complete instructions review the documentation that came with your equipment.