Designed for the Venta Airwasher models to maintain hygienic conditions in the lower housing and to improve the evaporation process. Creates a sheeting action on the disks with the effect of maximizing the amount of surface area. Prevents calcium and lime build-up and helps to keep the water more anti-bacterial. The ingredients of the Venta water treatment additive do not evaporate, they remain in the unit back until poured out for cleaning (approximately every 10 to 14 days). Fresh water should be added daily. 1 bottle is sufficient for approximately 1 season (5 months).