Q6 Why does an RO system have five or more stages in the filtration process? What is the purpose of each step?

The first filter is a 5 micron particle filter to remove dirt, rust, and other sediment.

The second filter is a carbon filter which removes organic chemicals, and most importantly, removes any chlorine from the water which can react with the RO membrane and damage it.

Third is a fine, 1 micron filter which further removes finer particles remaining after the carbon filter.

Fourth, the RO membrane, the heart of the system, will filter 95-99% of the dissolved contaminants from the water. The contaminants are washed down the drain, and pure water flows into a pressurized storage tank.

Fifth, after the storage tank and before the faucet, is another carbon filter to “polish” the water, removing any remaining odors or tastes.

If desired a remineralizing filter can be added as a sixth stage, or used in combination with the fifth stage carbon filter as a combination (fifth stage) “polishing-remineralizing” filter.