What Do You Call a Filter in Plumbing?

Point-of-Use Filters

• As their name implies, point-of-use filters are installed at the actual places where water is used inside a home. They include kitchen and bathroom faucets, washing machines and refrigerators. Filters using carbon or reverse-osmosis action through membranes remove chlorine, bad taste and bad odor from drinking water. Screw-on aerators at faucet spouts are simple metal screens that prevent debris from pouring out with water in kitchen and bathroom sinks. Mesh filters on incoming washing-machine water lines prevent dirt from entering washing machines as they fill with water.

Point-of-Entry Filters

• A point-of-entry filter is used at a home’s main water line where water enters from a municipal water supply or well. Whole-house filtration systems affect all fixtures and appliances, including those that are not serviced by point-of-use filters. Showers, bathtubs and dishwashers benefit from filtered water. Filters eliminate debris and scale deposits on fixtures and dishes, and they protect appliances such as water heaters against rust stains.

Conditioners and Softeners

• Water conditioners and softeners are not water filters, although some people call them filters. Water filters remove undesirable particles and chemicals from a water supply while water conditioners and softeners add, remove or replace salts and chemicals. Water-conditioning devices change calcium ions, rendering them unable to produce limescale and leaving water safe for drinking. Water-softening devices remove calcium and magnesium from water and add sodium, which reduces limescale but may affect the water's suitability for drinking.

Considerations

• Filters, regardless of type, can perform to maximum efficiency only when properly maintained. Screw-on faucet aerators need cleaning when sediment clogs their metal screens. Some regions have "hard" water, which increases scale deposits and the need for water softeners. Drinking-water filtration systems at kitchen and bathroom sinks can be under the counter or on counter tops. If space is a consideration, counter-top filters may be obtrusive. Although whole-house water filters are more expensive than point-of-use filters, they improve water quality throughout a home, and protect all fixtures and appliances.