An RO water purifier works on the basis of the process called Reverse Osmosis. In reverse osmosis process, a solvent is forced to cross over a semi-permeable membrane from a high concentration region to a low concentration region by applying pressure. This process is exactly opposite of the natural process called osmosis. As the whole process of water purification in your RO water purifier is based on the principle of Reverse Osmosis, the maintenance of the semi-permeable polymer-based membrane, popularly called RO membrane, is of utmost importance for the longevity and proper functioning of the RO Water Purifier. It is therefore also essential to get an overview of the working of the RO system in order to make sure its smooth operation.