How Reverse Osmosis Works Read more: http://www.reverseosmosisguides.com/how-does-a-reverse-osmosis-system-work/ In simple language, the reverse osmosis system works by passing the tap water through a thick membrane or filter that allows only the water to pass and blocks all the inorganic materials mixed in water like salt from crossing the membrane. This is the simple filtration technique used by all reverse osmosis systems. Now where the results could differ are the factors like incoming water pressure, water temperature, quality and type of membranes used in the system and also the type of materials present in the water. Source: http://www.reverseosmosisguides.com/