R.O Servicing FAQ: Help yourself
Q.1.  How does reverse osmosis work?
A:  In modern home units water, driven by normal city water pressure, flows first through a carbon pre-filter, which removes organic contaminants including chlorine and its by-products. Next, it enters the reverse osmosis membrane, a very tight, sheet-like filter that allows water to pass but rejects dissolved solids like sodium and impurities like lead and arsenic. Some of the water entering the unit is used to cleanse the membrane surface and flows to the kitchen drain pipes. The purified water is stored in a small storage tank until it is needed. When the ledge faucet mounted on the sink is opened, the purified water is forced by air pressure through another carbon filter, which gives it a final polish and from there to the ledge faucet.
Q.2.  How long will a reverse osmosis unit last?
A:  Virtually forever if you service it regularly and replace parts that wear out, like the storage tank and the ledge faucet. Typical membrane life is about 3 to 5 years, depending on the nature of the water that it’s processing.
Q.3.  Do reverse osmosis units need electricity?
A:  No, they run on water pressure. You need electricity only if you add an electric pressure-boost pump or an ultraviolet lamp. Standard units have neither and normally don’t need them.