About Reverse Osmosis
Q. How does Reverse Osmosis (also referred to as “RO”) work?
A. RO works by passing water through a semi-permeable membrane that separates the pure water into one stream and the salt water into another stream. The process is called “Reverse Osmosis” because it requires pressure to force pure water across a membrane, leaving the impurities behind.
Q. Why do they call it “Reverse Osmosis”?
A. In regular “Osmosis,” such as the process utilized by plants, water flows from a lower concentration of salts to higher concentrations. In “Reverse Osmosis,” the application of pressure greater than the osmotic pressure reverses the water flows from higher concentrations to much lower concentrations, producing pure water.
Q. Is this the best type of drinking water filter for my water?
A. This depends on the quality of the source water. Generally, if the water to be filtered is municipally-treated city water low in minerals, then less expensive carbon block filtration systems would be the best type. If the water is very high in minerals, then a reverse osmosis system or distiller that removes minerals, salts and chemicals may be desired.
Q. What do you mean when you say the water is “high in minerals”?
A. We mean that water that has a total dissolved solids (“TDS”) over 500 ppm or hardness over 200 ppm. However in some cases, even water that is lower than 500 ppm of total dissolved solids may need treatment by RO if there is some inorganic contaminant that needs to be removed. For instance, many customers are using an RO system who do not want to ingest the fluoride that is put into their water. Other contaminants that can be removed by RO include arsenic, or lead or other dissolved inorganic substances.
Q. How do I know what is in my drinking water?
A. If you are on city water, your local water must meet very strict Federal and State standards for purity. However, many areas use ground water (well water) high in minerals and salts. This can affect taste. All municipally treated water is chlorinated, and this can also affect taste and create odors in the water. If you are on a private well or spring, you should have your water tested. Contact AWS for specific recommendations.
Q. Will RO’ s remove hardness minerals or help cut down on scale build-up in coffee pots, etc.?
A. Yes! Most water contains “total dissolved solids” (TDS) , which is roughly the total inorganic mineral content of the water, and these are removed. The reverse osmosis membrane separates these dissolved solids, or salts and flushes them down the drain.
Q. Will these systems remove lead?
A. Yes. Both the RO membrane and the carbon block filter will reduce the lead. Carbon block filters use a lead-specific filter media combined with the carbon to reduce lead.
Q. Will these systems remove parasites or cysts?
A. Yes. The RO systems are certified for cyst removal.
Q. Is bacteria a problem with reverse osmosis systems?
A. Yes and no. We have tested many of our systems for total bacteria counts over the years and have not found higher levels after the systems unless the systems sat for several days in between uses. However, in some cases, particularly if the source water is high in bacteria and/or low in chlorine residual, bacteria can grow. We also have Ultra-Violet Sterilizer Systems that disinfect water after it leaves the filter system, insuring water low in bacteria. The manufacturers state in their warranty information that the RO systems are designed to be installed on water that is disinfected or does not have dangerous bacteria such as e.coli.
Q. Are RO systems difficult to install?
A. No. The RO systems come complete with all the tubing, fittings and items you need to install it. In some cases you may need to drill a new hole in your sink, or you can use an existing hole to install the RO faucet. Typically a plumber will take 20 minutes to read the installation instructions and 1 to 1-1/2 hours to do a professional installation, but many homeowners have installed these themselves.
Q. How often should I change the filters in an RO system?
A. The filters should be changed once a year. The membrane should be changed every 3 to 5 years depending on the TDS levels in the purified water.