The reverse osmosis water filter works by a series of pre-filters, the first of which the water be pumped through is the SW5 strung filter. This filter works to remove sediment and other particles down to the size of 5 micron. After this the water passes to allow pressure switch before going through to the booster pump. From the booster pump, it then passes through the second filter, this is the carbon filter that contains activated carbon, removing the chlorine from the water. Then the water is pumped through the third filter, the SW1 filter, which removes any particles still in the water down to a size of 1 micron. After the three stages of pre-filtration have occurred the water will then pass through the RO membrane where virtually all remaining contaminants are removed before moving on to the post-filter which also contains activated carbon that polishes your water by removing any unwanted tastes, purification of your water is complete and it is ready for you to drink.