PWP Double RO/DI System *Pure Water Power Double RO DI System Overview Increase the speed and effectiveness of your water fed window cleaning process with the Pure Water Power Double RO DI System. This powerful and cost effective purification system features dual ROs to significantly increase the gallons per minute output, enabling you to operate without the need for a pump. This helps you to clean taller windows and allows you to run two water fed poles. Filtration Process