Ordinary tap water is full of sediments and minerals. It’s these impurities that cause spotting and streaking when tap water is left to dry on a surface. For that reason, users of the water fed pole system use purified water. Window cleaners purify their water by passing it through a series of filters and resins, making use of natural processes like reverse osmosis and deionisation. They then store this water, usually in a suitably equipped vehicle, so that they can get it to their customers.The windows still have to be thoroughly cleaned. To do this, water fed pole window cleaning uses telescopic poles complete with cleaning brushes that can easily access heights of up to 70-feet. The pure water is then pumped up these poles, which allows the window cleaner to scrub and rinse away any dirt. Because the cleaning process has used pure water, the windows can then be left to dry naturally, with a perfect, crystal clear finish.