How Do Whole Home Water Filters Work?

Whole home water filters, also called point-of-entry (POE) systems, are designed to treat all the water entering your home. They are often installed at the point water enters your house so that every faucet, showerhead, and water-connected appliance downstream receives filtered water. This means cleaner and safer water for cooking, bathing, and everything in between.

By treating water for the entire house, whole home water filters provide filtered water for uses beyond drinking and cooking and may improve the efficiency and longevity of your plumbing and appliances by reducing corrosion and scale buildup. Furthermore, your laundry may feel softer and last longer, and your dishes and glassware may appear cleaner. If you want the convenience and peace of mind of having filtered water all throughout your home and not just your kitchen faucet, a whole home water filter might be ideal.

How Whole Home Water Filters Work, Step by Step

Whole home water filters often use multiple filtration stages to address a range of water quality issues and concerns.

STEP 1

Media Filtration (Activated Carbon/KDF)

Upon entering the system, the water flows into a tank containing activated carbon or other filtration media. Through a process called adsorption, the carbon pulls contaminants, such as chlorine, volatile organic compounds (VOCs), and pesticides, from the water and holds them onto its large porous surface. Copper-zinc (KDF) media is sometimes used to reduce chlorine levels, remove heavy metals such as lead and mercury, and inhibit the growth of algae and bacteria in the tank.

STEP 2

Postfiltration

Next, the water flows through a sediment postfilter that uses robust, layered mesh screens to catch sediment, such as dirt, silt, sand, clay, and rust, that may still be present in the water. Optional upgrades may also be made to the system to address other water issues, such as a UV purifier to destroy microbes and a water softener to combat hard water issues.

STEP 3

Treated Water Distribution

Once filtered, the water flows through your home’s main plumbing line and continues to every outlet and appliance, including faucets, showers, toilets, dishwashers, and water heaters. Now, you can access clean, safe filtered water nearly everywhere in your household rather than just a single location.

Whole House vs. Point-of-Use Water Filtration

Key Consideration	Whole Home Filter	Point-of-Use Filter
Coverage	Entire house; filtered water for drinking, cooking, showering, washing, cleaning, and more.	Specific location, such as the kitchen tap; filtered water for cooking and hydrating.
Common Contaminants Removed	Sediment, chlorine, chloramine, disinfection byproducts, pesticides, herbicides, some VOCs (optional add-ons available for wider treatment)	Lead, arsenic, fluoride, nitrates, PFAS, chlorine, chloramines, chromium-6, total dissolved solids (TDS); varies by POU filter type.
Cost	Higher initial investment	Lower upfront cost
Size and space requirements	Larger and bulkier, occupying more space.	Utility reports help, but at-home testing still catches plumbing-side issues
Ease of installation	More complex and time-consuming; May require professional help, but DIY is possible.	Easier to install; under-sink systems may require modifying your countertop.

What This Means for Maintenance

Whole-home water filters require regular filter changes and maintenance, or the entire water supply could be compromised. Follow this quick filter replacement schedule to help keep the system running efficiently and your water quality consistent:

POST-FILTERS

Change Sediment Postfilter Every 6 to 9 Months

Replace the sediment postfilter, or the sub-micro post-filter, to effectively capture particles that the sediment prefilter may have missed.

PRE-FILTERS

Replace Main Filter Every 10 years or 1,000,000 gallons

The main filter can last up to a decade when the prefilters remain fresh, but high contaminant loads, harsh chemicals, etc., may shorten the replacement interval to 6 years or 600,000 gallons.

Improve Your Home’s Water Quality with a Whole Home Water Filter

With a POE filter, you can find peace of mind knowing your home’s water supply is cleaner and safer for drinking, cooking, showering, and other uses. Plus, you can customize your system to match your specific needs. Explore our selection of premium whole home water filters to find the right one for your home.