Home Water Filter Basics

The United States in general has high water quality standards and most of the water that comes out of our home water taps is clean and pure. However, even clean and pure water can have odors or appear cloudy, characteristics a water filtration system can improve. In fact, a home water filter system can rectify the overall appearance, taste and smell of tap water, plus remove some chemical contaminants in the water. If you'd like to improve some aspects of your home's drinking water, here's some basic information on home water filters.

Two home water filter designs:

  • Point of use devices are small appliances designed to treat g and drinking water. They’re usually installed on a tap, but can simply be pitchers where water is poured into the top then works it’s way down thorough a filter by gravity.
  • Point of entry devices are larger units installed onto a homes water supply and they filter all the water entering a home. Since these units are designed to treat larger volumes of water point of entry filters need to be plumbed into the home’s water system (making them more costly than point of use filters).
    Filtering Process

Home water filters utilize one of three filtering methods.

Particle Filters

  • These designs use a membrane or screen to trap particles suspended in the water and filter them out. Their filtering capability depends on the size of the openings in the membrane (measured in microns or millionths of an inch). The lower the number of microns, the smaller the openings in the pores and the more effective the filter.
  • Particle filters are commonly made from either fiber ( rayon or cellulose) or ceramics, that trap particles of dirt, floating fibers, as well as some bacteria and parasites (although not enough to purify the water). They won’t remove any dissolved chemical contaminants.
    Activated Carbon (AC) filters
  • AC carbon filters are effective at improving the taste, appearance and odor of water because they are effective at removing the organic contaminants that cause these problems.
  • 'There are two types of AC filters, Granular Activated Carbon filters that use a cartridge packed with carbon granules and Solid-Block Activated Carbon filters that (not surprisingly) uses carbon in a block form. With either type of carbon filter, the carbon granules or the small pores in the carbon block trap particles and absorb substances dissolved in the water, like chlorine, metal or pesticides.

Resin Filters

  • Use resins to remove contaminants and minerals that cause deposits to from in water pipes and on appliances such as coffeepots.
  • Resin filters are sometime combined with Carbon Activated Filters to provide ‘double filtering’ of water to better remove both dissolved chemical substances and particles.

Should I get a water filter?

  • If you’re concerned about the quality of your tap water, boiling before drinking is the best way to ensure there are no living microorganisms in it.
  • However, if you find your water has a flavor your don’t like, appears cloudy or dirty or has a nasty odor, a water filter will definitely improve it.
  • Home water filters are designed for use with micro biologically safe water and no single water filter can remove all types of substances from water, so you may need to look at a few to find one that can address your particular concern. However, the good news is water filters are generally labeled and tell you what they will remove.
Murray Anderson is an experienced freelance writer with over 800 articles published on the web as well as in print magazines and newspapers in both the United States and Canada. He writes on a wide range of topics and is a regular contributor to DoItYourself.com. He can be contacted at [email protected].