Abstract: A portable winterization system for replacing water in a recreational water system with antifreeze. An inverted container is provided for holding a volume of antifreeze, the container having an aperture at an upper portion thereof. A Tee connector has three ports orthogonally disposed with respect to one another, the upper one of the ports being connected to a lower portion of the container. A support stand is connected to a lower one of the ports of the Tee connector for supporting the Tee connector and the container. A middle one of the ports of the Tee connector is adapted to connect to a water inlet port of the recreational water system. The system can also be used to sanitize potable water lines in recreational vehicles as well as motorhomes, fifth wheels, travel trailers, boats, seasonal homes, hot tub jets, and tagalongs.