How to Choose a Water Filter for Your Home in 8 Simple Steps

By HomeAdvisor

Updated March 22, 2023

woman filling water bottle from tapPhoto: baloon111 / iStock / Getty Images

Do you know what’s floating in your tap water? In the United States, we often take for granted that water coming from the tap is safe to drink. Still, trace levels of germs, chemicals, and minerals make it into the water we use to drink, bathe and wash every day.

A water filtration system can help remove these impurities. But, with so many options available, it can be overwhelming deciding how to choose a water filter.

Let us walk you through common water contaminants, how water filtration systems work, questions to ask when choosing a water filter, how much water filtration systems cost, and the benefits of adding a water filter to your home.

Read on to find out which water filter is right for you.

How Dirty Is Your Water?

Even though U.S. water supplies are considered among the safest in the world, contamination occurs daily through several sources, including:

  • Sewage releases
  • Fertilizer and pesticides used on local land
  • Malfunctioning wastewater treatment systems (like septic systems)
  • Improperly maintained distribution systems (like rusty pipes)

Common contaminants include:

  • Lead
  • Nitrate
  • Arsenic
  • E. coli or coliform bacteria
  • Cryptosporidium parasites

If your local health officials have ever issued a boil water advisory, you know how disruptive contaminated water can be. Beyond boiling water, a well-maintained water filtration system will have you prepared for such an event.

How Do Water Filters Work?

In general, home water purifiers filter your water in two ways.

  • Physical filtration: Provides a barrier to remove solid particles from water via filtration, sedimentation, or distillation.
  • Chemical filtration: Creates a chemical reaction inside the filter to remove chemical contaminants like metals via ultraviolet light or chlorination.

No water purifier eliminates every contaminant, so you should ask yourself a few questions to determine what you want out of your filtration system.

5 Key Questions for Choosing a Water Filter System

two women in kitchen making foodPhoto: Edwin Tan / E+ / Getty Images

You may be wondering, “Which type of water filter is best?” Answering the following questions will help you narrow down the best water treatment system for your needs and budget.

1. Why Do You Need a Water Filter System?

Your motivation for installing a water filter system will help narrow down which one is best for your home. For example, if you just want your tap water to taste better or are interested in conserving water at home, then attaching a basic filter to your tap could suffice.

Alternatively, if you have reason to believe your home’s water supply is compromised, you’ll want to consider more advanced whole-house or point-of-entry systems to treat all water entering your home.

2. Do You Have Well or City Water?

Identifying where your water comes from is useful for finding out what kind of contamination is in your water.

According to Center for Disease Control and Prevention (CDC) data, over 90% of Americans get their tap water from community water systems. The Environmental Protection Agency requires city water providers to meet certain safe drinking water standards and provide documentation of contamination levels to customers on an annual basis.

That leaves over 15 million homes that draw water from unregulated private wells. If you have well water, you will need to test the water yourself or seek a third party’s assistance.

3. How Many Contaminants Are in Your Water?

You should know what’s in your water to determine your treatment needs. Here’s how to find out, based on your water provider:

In either scenario, you can also find a local water purification professional to test and treat your water.

4. How Much Filtered Water Do You Need?

Filters vary in capacity and speed. Some filter large amounts quickly, while others are slower. If you’re interested in cleaner drinking water for yourself, then a pitcher filter would be suitable. On the other hand, a faucet or under-sink filter may be necessary to provide water for larger households.

5. How Much Does A Water Filtration System Cost?

Water filtration systems range from simple DIY systems that cost around $20 to complex systems that cost between $600 to $4,200 and require professional installation.

All water purification systems also need maintenance to continue functioning properly. Before making a purchasing decision, you should factor in how much maintenance your system will require, how often filter cartridges need to be replaced, and how much replacement filters cost.

Which Water Filtration System Is Right for You?

When choosing a water filtration system, you’ll be selecting from two varieties:

  • Point-of-use (POU) systems treat and deliver water through a single tap, such as a kitchen sink, shower, or washer. POU systems are more commonly used to address the smell or taste of a given source’s water.
  • Point-of-entry (POE) systems treat the main water line where water enters your home and filter all water entering your house. POE systems more thoroughly address the health of your drinking, washing, and cooking water.

Between POU and POE systems, there are numerous options available. Here are a few of the most common, how they work, and how much they cost.

Whole-House Water Filter

These are POE systems that treat all water entering your home. Whole-house filtration systems often have multiple filters that eliminate contamination, including:

  • Sediment filter: Removes solids
  • Carbon filter: Removes chlorine
  • Reverse osmosis membrane: Removes compounds and reduces dissolved impurities
  • Deionization filter: Removes most remaining dissolved solids
  • UV light: Sterilizes water from any remaining living organisms

Pros of whole-house water filters:

  • Single solution for your water filtration needs
  • Can be used to treat volatile organic compounds (VOCs)
  • Useful for softening hard water

Cons of whole-house water filters:

  • Typically a more costly option
  • May require plumbing modifications and professional maintenance
  • Removing chlorine could spread germs throughout the pipes in your house

Installing a whole-house water filter costs $600 to $4,200 depending on the type, the number of stages of filtration, and how many gallons it can clean.

Faucet-Mounted Filtration

someone filling up glass with water from sinkPhoto: Cucurudza / iStock / Getty Images

Faucet-mounted filters are POU systems that attach to an existing faucet and can be turned on and off for filtered water flow.

These units effectively remove contaminants for better-tasting drinking water. However, without proper maintenance, the seal between the faucet and the water filter can quickly deteriorate.

Pros of faucet-mounted filtration:

  • Easy to install
  • An affordable option

Cons of faucet-mounted filtration:

  • Low durability
  • Can slow water flow

Reverse Osmosis Filtration

Reverse osmosis systems sift out particles using a high-pressure pump and filter water through a membrane. They typically use a process with three or more stages to remove impurities. They can either be installed as POU or POE systems.

Pros of reverse osmosis filtration:

  • Most effective in eliminating disease-causing organisms and chemical contaminants, including metals and nitrates
  • Provides excellent drinking water
  • Can be used for water softening by removing sodium

Cons of reverse osmosis filtration:

  • Requires higher maintenance and regular filter changes
  • Uses roughly three times as much water as it treats
  • May require an additional system for disposing of wastewater

A POE reverse osmosis system costs $800 to $2,800 on average, while a POU system installation costs $150 to $1,300.

Under-Sink Water Filter

under sink water filter in kitchenPhoto: Bluewater Sweden / Unsplash

Under-sink water filters are POU systems that are installed underneath sinks and send water through a pipe to the filter’s own specially installed faucet.

If you receive municipal water, these are a popular option if you want to filter for drinking and cooking but aren’t concerned about showers, laundry, or dishwashers.

Pros of under-sink water filters:

  • Filter large amounts of water
  • Produce very high-quality water for drinking and cooking
  • Low maintenance with infrequent filter changes

Cons of under-sink water filters:

  • Higher installation cost
  • May require modifications to plumbing and professional installation

Installing an under-sink water filter costs $150 to $1,200 depending on the system and if you DIY it or use a professional. Repairing under-sink water filters costs between $150 to $300, so they are usually more affordable to replace if needed.

Carbon Filter

Carbon filters are the most common water purification system. They are POU systems that attach directly to a single faucet or are used in pitchers to remove organic compounds when water comes in contact with a carbon cartridge.

Pros of carbon filters:

  • Affordable, with prices ranging from $30 to $100
  • Better-tasting water
  • Removes unpleasant tastes, odors, fuel products, and/or pesticides from water

Cons of water filters:

  • Cartridges have to be replaced periodically
  • Specific compounds like lead or asbestos will require a specially made and certified carbon filter

UV Light Water Treatment

Ultraviolet light water treatment neutralizes living organisms but leaves chemicals and heavy metals in water. While highly effective at removing bacteria and viruses, UV light does not affect dissolved solids (like rust or arsenic) and is ineffective in murky water.

Pros of UV light water treatment:

  • Quick purification process
  • Easy maintenance requires only lightbulb and standard filter replacements annually
  • Uses light instead of chemicals to treat water, so the taste is not affected

Cons of UV light water treatment:

  • Not used as a standalone treatment, requiring additional treatment systems to filter impurities
  • Needs electricity to function
  • Works best with clear water

Installing a UV light water treatment system costs $500 to $1,500 or more.

Water Filters vs. Water Bottles

Many believe that water bottles are a safer and tastier alternative to tap water. However, installing a water filter instead of using single-use bottled water offers numerous financial, environmental, and safety benefits.

Household Savings

Purchasing a gallon of bottled water is between 240 to 10,000 times more expensive than purchasing a gallon of tap water. Ironically, government and industry estimates show that roughly one-fourth of bottled water consists solely of tap water.

Rather than paying exponentially for bottled tap water, installing a water filtration system can supply you with quality drinking water for a fraction of the cost.

Amount you are paying for bottled waters infographicPhotos: PeopleImages / iStock / Getty Images, vitapix / E+ / Getty Images, mladenbalinovac / E+ / Getty Images, LightFieldStudios / iStock / Getty Images, BraunS / iStock / Getty Images

Environmental Benefits

Water bottles are a major source of environmental pollution, with nearly 22 billion bottles ending up in U.S. landfills annually. An effective water filtration system can provide better-tasting drinking water and reduce the amount of plastic waste produced annually.

What happens to discarded water bottles? infographicPhoto: themists / iStock / Getty Images

Health and Safety Standards

It’s commonly believed that bottled water is safer to drink than tap water. Yet, municipal water suppliers may be subject to much stricter water safety standards than bottled water manufacturers.

Here are a few examples of how safety standards differ:

  • City tap water can have no confirmed E. coli or fecal coliform bacteria, while the presence of fecal matter contamination is not prohibited for bottled water.
  • Bottled water plants must test for coliform bacteria once a week, while city tap water must be tested 100 or more times per month.
  • City tap water must meet standards for toxic chemicals like phthalate, while bottled water is exempt from these regulations.
  • City water systems must issue annual Consumer Confidence Reports detailing what is in their water, while bottlers do not.

Is bottled water safer to drink? infographicPhotos: mladenbalinovac / E+ / Getty Images, BENCHAMAT1234 / iStock / Getty Images, AwaylGlt / iStock / Getty Images

DIY vs. Professional Installation

woman fixing plumbing under sinkPhoto: Rawpixel / iStock / Getty Images

Installing a basic point-of-use system is generally suitable for all skill levels. There are many DIY kits available that usually require screwing connections onto your sink pipes.

More complicated point-of-entry systems will require professional installation and maintenance because of their direct connection to your home’s plumbing.

Hiring a local water filtration professional to help with installation is the safest way to make sure your system works properly. An experienced professional can also discuss your options and provide expert advice about which system makes the most sense for your home.

Now that you know how to choose a water filter, find trusted local pros in your area to help with a seamless installation and start enjoying clean tap water today.

The case for tapwater over water bottles infographicPhotos: dusanpetkovic / iStock / Getty Images, PeopleImages / iStock / Getty Images, vitapix / E+ / Getty Images, mladenbalinovac / E+ / Getty Images, LightFieldStudios / iStock / Getty Images, BraunS / iStock / Getty Images, themists / iStock / Getty Images, mladenbalinovac / E+ / Getty Images, BENCHAMAT1234 / iStock / Getty Images, AwaylGlt / iStock / Getty Images, luchschen / iStock / Getty Images, bedya / iStock / Getty Images, Daniil Dubov / iStock / Getty Images


According to Statista, Americans consume 45.2 gallons of bottled water per capita. If the average cost of a 20-ounce bottle of water is $1.50, a gallon of bottled water is $9.60. 45.2 gallons x $9.60 = roughly $433.92 per person spent on bottled water. If the average cost of a gallon of tap water is $.004, 45.2 gallons x $.004 = $0.181. 433.92/.181 = $2,397.35.

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