A good humidifier is only as good a its wick. Be sure to always use Essick Air brand wicks/filters which have been independently tested to ensure they meet high standards. Replace your wick at least once per season, or more often under hard water conditions. Use with EA-1201 Humidifier. WARNING: This product can expose you to chemicals including benzene which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.