First, the water is softened so that the very fine filters used through the rest of the process won't be damaged by too much wear and tear. Then the softened water goes through a series of filters which each refine the water more than the one before. The very last, and most thorough, stages of filtration use a method called "reverse osmosis" ... it would take more than this one paragraph to explain that fully, but all you need to know is that it removes all organic, bacterial or particulate impurities from the water. By the time the water reaches the end of this process the level of impurities in the water is less than 30 parts PER MILLION!
But we don't stop there ... we want the best possible finish for your windows and so we need the purest water possible. Making water this pure involves one final stage known as "de-ionisation" ... this is another complicated process, but we explain it as filtration on an atomic level. De-ionisation removes even the last few atoms of impurities from the water. By the time the water has been through this final stage the impurities have dropped to below 1 part per million. You won't find water much purer than this except in certain scientific research facilities, and it's only now that we are ready to clean your windows!
