Whole House Water Filter Systems: What They Remove and Cost

What does a whole house water filter remove?

A whole house water filter mainly removes sediment and reduces chlorine taste and odor at every tap. Carbon stages can also reduce some organic chemicals and, in some filters, metals like lead. It does not remove calcium and magnesium, so it won't soften water or stop scale. For that you need a softener.

Most whole-house systems use one or more of these stages:

• Sediment filter: catches sand, rust and other particles.
• Activated carbon: reduces chlorine taste and odor and some organic chemicals.
• Catalytic carbon or specialty media: used when a pro finds a specific issue, such as chloramine or iron.

University of Arizona Cooperative Extension says activated carbon can reduce:

• Unwanted taste and odor, and residual chlorine
• Low levels of some organic chemicals, such as pesticides and solvents
• Radon
• Lead, copper and mercury (only some carbon filters; check certification for the specific contaminant)

It also notes that carbon does not remove major minerals, soften water or disinfect it.

Is a whole house water filter worth it in the Phoenix area?

Phoenix-area water comes mostly from rivers. The City of Phoenix reports that roughly 97 to 99 percent of its supply is surface water from the Salt, Verde and Colorado rivers, delivered through SRP canals and the CAP aqueduct. Surface water is disinfected before it reaches you, which is one reason some people notice a chlorine taste or smell. Details for your city are on our water softener locations page, starting with Phoenix.

Phoenix also blends CAP and SRP water partly to improve aesthetics, and the mix changes with the seasons. If taste or odor shifts through the year, a carbon filter may help.

The City of Phoenix says home filters are typically not necessary unless your doctor advises one, so for most homes this is a comfort upgrade. To treat something specific, start with a water test. Check how hard your city's water is in our Phoenix water hardness guide.

Sizing and installing a whole house filter

Flow rate and placement

A whole-house filter must handle your home's peak water flow without hurting pressure. The installer considers the number of bathrooms, your main line size and how many fixtures run at once. Systems usually go where the main line enters the home, often in the garage near the softener loop, and include a bypass valve. In the Phoenix heat, ask whether any part of the system will sit outdoors or in direct sun, and how it will be shaded or protected.

Pairing a filter with a softener

If you also plan a softener, install them together. The carbon stage protects softener resin from chlorine, which can help the resin last longer, and one plumbing visit is usually cheaper than two.

Because a whole-house system ties into your main water line, it should be installed by a licensed contractor. In Arizona that is typically a water conditioning (R-54) or plumbing contractor; you can verify any license at azroc.gov.