A chamber has upper end and lower ends. A base has an annular trough receiving and supporting the lower end of the chamber. When water is within the trough, air flowing through slots in the lower end of the chamber becomes moisture laden. A fan in the chamber directs the air flow in a recirculating path of travel. A carbon dioxide tank in the chamber dispenses carbon dioxide into the recirculating path of travel of the air flow. A solenoid has an input line coupling the tank and the solenoid and an output line with an exterior extent with apertures and a foam covering constituting a reservoir. A control assembly activates and inactivates the fan and the carbon dioxide tank in a timed sequence.
