Water Filter Glossary



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Water Filter Glossary - In Words We Can All Understand

AC – Activated Carbon

Big Blue - Refers to filter cartridges that are 10" or 20" long and 4" in diameter and the 10" or 20" housings that they fit in. Big blue cartridges and housing are typically used where higher flow rates and water usage is needed.

CB – Carbon Block

CTA - Cellulose triacetate membrane - the CTA membrane is prone to rotting unless protected by chlorinated water. In CTA systems, a carbon postfilter is needed to remove chlorine from the final product water.

GAC - Granulated Activated Carbon

GPD – gallons per day - this is the number of gallons of water a system will filter in a 24 hour day.

Hard Water - Hard water is water that contains mineral salts (as calcium and magnesium ions) that limit the formation of lather with soap; Hard water reduces the cleansing power of soap and produces scale in hot water lines and appliances. Hardness can be removed by ion exchange.

MTBE - Methyl-t-butyl ether (MTBE) is typically added to unleaded gasoline to reduce its carbon monoxide and ozone content. MTBE makes its way into drinking water through several sources, including leakage of underground storage tanks, fuel spills, emissions from marine engines, and, to a small extent, condensation of exhaust fumes. Because MTBE is a relatively new contaminant, the EPA is currently conducting tests to clarify the potential health effects of ingesting MTBE in drinking water.

POE - Point of Entry - Water filter designed to filter water as it enters your house rather than at each faucet.

POU - Point of Use - Water filter designed for use at each faucet as opposed to a system to filter water for the whole house.

RO – Reverse osmosis - Water forced under pressure through a semi-permeable membrane rejects inorganic contaminants, leaving high quality water for consumption. One of the most effective point-of-use water treatment technologies available today.

TDS – Total dissolved solids. Inorganic material such as heavy metals and rock that are dissolved in the water.

TFC - Thin Film Cellulose Membrane - A molecular sieve constructed in the form of a film from two or more layered materials. Membranes used in reverse osmosis are typically made out of polyimide, chosen primarily for its permeability to water and relative impermeability to various dissolved impurities including salt ions and other small, unfilterable molecules. The TFC membrane is prone to breaking down under the influence of chlorine.

TFM - Thin Film Membrane - Same as TFC above

UV - Ultra Violet - Used to eliminate any bacteria that may be missed in the filtering process.

VOCs – Volatile organic compounds