Reverse osmosis and ultrafiltration vary a great deal. Reverse osmosis is able to reject dissolved minerals in the water, whereas UF only filters solids or particulate. Reverse osmosis can get out dissolved inorganic minerals that could go through the UF membrane. How can we allow you to? Water, Inc. http://waterfiltersystemblog77899.jiliblog.com/24624326/the-best-side-of-water-filters-blog