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Types of Water Filters Fact Sheet

by Sam N. Austin

Purified water

Water filters serve a range of household purposes, from improving the taste of tap water to removing contaminants. So it's no surprise that water filters are so popular in households everywhere. If you want to start enjoying clean, filtered water in your home, take some time to learn about your options before you buy. Choose from a wide range of water filter types; a quick look at the differences between them can help you choose one that best fits your needs.

Water Filter Facts:

  1. Types of systems: Water filters are available in different form factors, such as water filter pitchers and faucet water filters for drinking water and large under-sink water filters or whole house water filters. Pitcher filtration systems, where the water drips through the filter directly into the pitcher, are convenient for keeping purified water in the refrigerator, while faucet attachments offer the option of filtering water continuously right out of the tap. For areas where the water supply is a concern, reverse osmosis and other large-sized filtration units can filter water for the household even before it reaches the tap.

  2. Filtration methods: Different water purifiers use different methods of filtration. One method is to run water through filters that trap contaminants and remove them from the water. Filters, often in pitcher-style and faucet-attachment systems, can be made of activated carbon or charcoal and can remove contaminants as well as unpleasant tastes and smells. Faucet and pitcher filtration methods allow you to filter small volumes of water, such as a gallon or less. A second method, reverse osmosis, uses a high-pressure water flow through a specialized type of filter called a membrane and can include multiple filtration stages. Reverse osmosis systems, which often fit under a sink or at the point of the household's main water supply, can filter large volumes of water for multiple uses.

  3. Uses: Water purifiers can improve the taste of drinking water, remove unpleasant odors and generally make drinking water more enjoyable. You can also use reverse osmosis filters to remove organic contaminants, such as bacteria and microbes, from your water supply. All filtration methods are designed to remove inorganic matter, such as chlorine and lead, from your water supply, which can improve both the taste and the color of your water.

  4. Certifications: The U.S. Environmental Protection Agency (EPA) recommends that you look for one or more of three certifications when choosing a water filter. These certifications are from the Underwriters Laboratories, the Water Quality Association and NSF International. The certifications, which may appear on the product's packaging or on the product itself in the form of an icon or similar mark, can also help to ensure that a particular filter addresses the specific uses you have in mind when buying a water filter.

  5. Considerations: Most water filters use types of filters that will eventually need to be replaced. The frequency with which a filter needs to be replaced varies depending on the individual product and may be noted on the product's packaging. Some products provide the information in terms of gallons of water filtered, while others refer to timelines, such as one or two months. It is helpful to take into account both the cost and availability of replacement filters when choosing a water filter.

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