Should I Install a Whole House or Tap Water Filter?

Choosing the right water filtration system can be a challenging decision, especially with the array of options available.

This guide aims to help you decide between installing a whole house water filter or a tap water filter by considering critical factors like water quality, household size, budget, and health concerns.

 

Understanding Your Water Quality

Before deciding on a filtration system, it’s crucial to understand the current quality of your water. A water quality test will assess:

• pH levels

• Water hardness

• Presence of contaminants like lead, chlorine, and bacteria

Knowing these details will help you make an informed choice about which filter is best suited to your needs.

 

Always choose a reputable licensed plumber to install any water treatment products in your home. Improper advice and installation could introduce more contaminents instead of making your water safer!

 

Household Size

Whole House Filters

Whole house filters are ideal for households with 2-4 people or more, ensuring that every water outlet in the home provides clean, filtered water.

Tap Water Filters

Tap water filtersr are suitable for smaller households but may require multiple units to cover various points of use like kitchen sinks and bathroom taps. They can be used in conjunction with whole house filters to further purify drinking water.

 

Budget Analysis

Whole House Filters

While house filters typically have a higher initial cost but can be more cost-effective in the long run, particularly for larger households.

Tap Water Filters

Tap water filters have a lower initial cost but may require frequent filter replacements, especially if multiple units are needed. They filter water at the tap, helping to eliminate any contaminants in older water pipes.

 

Types of Water Filters

Whole House Filters

• Carbon Block Filters: Effective for removing chlorine, sediment, and some volatile organic compounds (VOCs).

• Reverse Osmosis Filters: Removes a wide range of contaminants, including heavy metals and bacteria, but can be costly and may require professional installation.

Tap Water Filters

• Carbon Block Filters: Ideal for point-of-use filtration, removing chlorine and improving taste.

• Reverse Osmosis Filters: Effective but only suitable for specific taps, often used in kitchens.

Impact on Water Usage

• Whole House Filters can slightly affect water pressure and overall usage since they filter all water entering the home.

• Tap Water Filters generally have a minimal impact on water pressure and usage as they are point-of-use systems.

Decision Matrix

Factor	Importance	Whole House Filter	Tap Water Filter
Water Quality	5/5	Broad range of contaminants	Effective at point of use
Household Size	4/5	Beneficial for larger homes	Suitable for smaller homes
Budget	4/5	Higher initial cost, long-term savings	Lower initial cost, potentially higher long-term cost
Water Usage	3/5	Slight effect on usage	Minimal impact
Water Quality Problems in Locality	5/5	Comprehensive solution	Targeted solution

Search for NSF Certified Drinking Water Treatment Units and Water Filters here:

https://info.nsf.org/Certified/dwtu/

You can check any model you’re considering purchasing by manufacturer, or search by manufacturer, brand, product type, and more. You can even individually select any of hundreds of items you’re trying to filter out to find an appropriate system that’s certified to remove those particular contaminants.

Learn more about product certification on the Water Quality Association’s website here, including a short video about contaminants in U.S. drinking water and the importance of using third-party certified filtration systems (and how to identify legitimately certified systems):

Product Certification

Don’t forget that the faucets, pool supplies, and other plumbing products you use in your home can also introduce contaminants into your water supply. Learn more about which products and manufacturers are safest here:

https://www.ul.com/industries/products-and-components/water-and-plumbing

At the above link, you can also find lots of information about certifications for drinking water system components, rough and finished plumbing products, water filtration products, and rainwater catchment systems. You can also find information about certifications for electrical safety for water products and sustainable practices of various manufacturers.

Health Concerns and Contaminants in Our Water

Impure water can lead to a range of health issues including gastrointestinal problems, reproductive issues, and neurological disorders. Both whole house and tap water filters can mitigate these risks, but their effectiveness depends on the type and extent of contamination.

Below we will go through a detailed list of many common contaminants in our water supply including the following, why you may or may not want to filter them out of your household water, and which filtration system is most effective.

• Hard Water (Calcium and Magnesium)
• Metals and Metalloids
• Sediment
• Trace Minerals
• Microorganisms
• Algae
• Pesticides and Herbicides
• Nitrates
• Mineral Salts of Natural or Human-Made Origin
• Chlorine and Chloramines
• Forever Chemicals (PFAS)
• Radionuclides
• Radon

 

Hard Water

Calcium and magnesium are found in high concentrations in hard water. Hard water can cause build-up in your faucets, pipes, dishwashers, and washing machines.

Hard water can be treated with a whole-home water softener or a TAC water conditioner. Moderate water hardness can be filtered out with a reverse osmosis system, an electromagnetic water descaler, or an ion exchange water filter. If your water hardness is a temporary problem, you can boil your water and use softening products in your washing machine and dishwasher.

If you choose to use a reverse osmosis system to remove calcium and magnesium from hard water, these elements will build up on the semi-permeable membrane over time and require replacement to remove clogs.

In terms of effectiveness, a water softener typically yields the best results when utilizing ion exchange and therefore would be best for softening your whole home water supply.

Always choose a reputable licensed plumber to install any water treatment products in your home. Improper advice and installation could introduce more contaminents instead of making your water safer!

Second most effective is a TAC Conditioner, which works through template-assisted crystallization. This will also treat your whole home water supply and is salt-free, which can be important to people with high blood pressure who are concerned about the cumulative effects of adding sodium to their water with water softener salt.

Other methods of softening water that are effective, but a bit less effective than the two above, are electronic descales, reverse osmosis, chelating agents, ion exchange filters, and boiling water. Sodium bicarbonate is a softening agent that can be used in washing machines to reduce the amount of detergent needed and soften water for laundry. Other products are also favorable to lessen the effect of hard water in washing machines as well as dishwashers.

 

Metals and Metalloids

Lead and copper, which while tested in public water to meet EPA standards, can be introduced in the pipes that come into your home, or from your own home’s water pipes.

Metaloids such as arsenic, boron, silicon, which are introduced into our water supply through the process of natural erosion of rocks. Arsenic in particular is commonly found in well water due to its high prevalence in ground water.

Heavy metals and other dissolved contaminants such as natural minerals can be removed by reverse osmosis systems as well, however not completely.

You can monitor your water with a Total Dissolved Solids monitor whether or not you have a filtration system so you’re alerted of any heavy metals in your water supply. These are available at various price points from very inexpensive to professional quality.

 

Sediment

Reverse osmosis filtration systems include a pre-sediment filter to remove sand and dirt from your water and keep it from clogging or damaging the other parts of your water filtration system.

 

Trace Minerals

Fluoride is also added to our water supply with the intention of reducing tooth decay. But not everyone wants fluoride in their water, and reverse osmosis water filters are capable of removing much of it. For those who may be concerned about this additive being filtered out by a home filtration system, fluoride toothpaste is available for daily dental care.

 

Microorganisms

Pathogenic bacteria, viruses, and parasites are a prevalent health risk associated with drinking water. Giardia and Cryptosporidium are two parasites commonly found in tap water. This is of particular concern in vulnerable populations. Contamination can occur at the source, the treatment plant, or during distribution, and can result in disease outbreaks.

Low-level, ongoing contamination can also lead to acute and chronic health effects, even when public health surveillance doesn’t flag contaminated drinking water as the source of the problem. Once introduced into the body, an infection may resulted in pathogens multiplying in their host, and certain waterborne pathogens may also reproduce in food and beverages, raising the chance of an infection.

While some pathogens such as noroviruses and Cryptosporidium are host-dependent and cannot grow in water, they may persist long enough to infect a new host. Other pathogens such as Legionella, however, can grow in water and are a cause for concern.

Your municipal water bill may list such contaminants in your local water when detected so you can be informed of the levels of contaminants in your household water.

However, regardless of a country’s socioeconomic development, detection of waterborne disease outbreaks are often not detected, and treatment process efficiencies vary among specific types and strains of microbes, including faecal pollution of public drinking water.

A portion of infected people may be asymptomatic depending on the pathogen involved, whole others may be more severely affected. Pathogens undetected by public water monitoring systems can include E. Coli, infectious hepatitis, Shigella, cholera, typhoid, and others can lead to severe disease. Others such as noroviruses and Cryptosporidium typically are self-limiting diarrhea diseases that do not cause severe disease, however, they can certainly pose a risk for more vulnerable people.

Due to the frequency of failure to detect such pathogens, additional filtration methods are recommended to keep your water safe.

To avoid contamination when changing your filters, the Center for Disease Control and Prevention recommends wearing gloves and disposing of the spent filter responsibly.

Some water filtration companies offer a recycling program for their used filters, so check with the manufacturer to find out if your filter is recyclable.

While chlorine is added to public water as a disinfectant (more on this later), many people prefer to filter it out due to the smell, taste, and possible health effects. Carbon filters are available in reverse osmosis that filter out chlorine, but only those certified for chlorine removal by the National Sanitation Foundation. Be sure to check for this certification if you’re looking for chlorine filtration in your home water.

If chlorine is filtered out of household water via a whole house filter, it would be advisable to test for waterborne pathogens at the tap, such as Legionella, Naegleria fowleri, Vibrio cholerae, Acanthamoeba, and others, that might be present in your home’s water pipes.

 

Algae

Poisonous cyanotoxins generated by blue-green algae that breed in warmer water are yet another contaminant that can be found in our drinking water. During an algal bloom, municipal water treatment may not remove all of these toxins which can cause brain and nerve damage, and be toxic to the liver.

However, high quality reverse osmosis can be an effective method of removal.

 

Pesticides and Herbicides

Depending on the reverse osmosis system you choose, your filtration system may also be capable of filtering out over 99 percent of pesticides and herbicides, but many of these systems do not filter the majority of these contaminants.

Not all systems are sufficiently effective, so research carefully before selecting a reverse osmosis system for your home, and look for a thin film composite semi-permeable membrane for this type of filtration. These have various compositions, so ask the manufacturer if the packaging does not clearly specify a high filtration of such contaminants.

Note that semi-permeable membranes that are listed as cellulose acetate (CA) or polyamide are not likely to be effective even if the manufacturer claims they are.

 

Nitrates

Nitrates are common in our water supply from agricultural run off and around manufacturing plants, as well as septic systems, and can become more concentrated when water is boiled.

These can be removed by reverse osmosis systems, but not by carbon filtration alone.

 

Mineral Salts of Natural or Human-Made Origin

Sulfates can be formed by decaying plant and animal matter, or as byproducts of mines, steel mills, tanneries, and textile manufacturing.

They are also found in cleaners and personal care products including laundry and dish detergents, hand soap, shampoo, lotion, styling gel, shaving cream, exfoliants, makeup remover, foundation, lip balm, toothpaste, mouthwash, bath bombs, salts, and oils, sunscreen, food additives, and much more.

They’re used in cleansing and foaming products because they lower the surface tension between ingredients and care therefore called “surfactants.”

The most common sulfate compounds in consumer products are sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES).

Sulfates can get into our water supply from acid rain, industrial runoff, or household waste, then build up in higher concentrations and make our water smell like rotten eggs and cause gastrointestinal issues.

A well-maintained reverse osmosis system can remove the majority of sulfate.

 

Chlorine and Chloramines

Chlorine is commonly used as a disinfectant by water treatment plants. Trihalomethanes (THMs) are a chemical disinfection byproduct (DBP) that occur in municipal water disinfected with chlorine. These DBPs are not typically found in groundwater and private wells, unless the well is being chlorinated.

THM contaminants include chloroform, bromodichloromethane, bromoform, and dibromochloromethane, and are found in varying concentrations depending on the water temperature, organic material present in the water supply, and the quantity of chlorine used.

These byproducts are a known high risk for the health of pregnant women and can cause problems during pregnancy, miscarriages, and low birth weight, as well as having been linked to colon and bladder cancer. Other health effects can include nausea, drowsiness, dizziness, kidney and liver damage, skin irritations, decrease in immune response, unconsciousness, fitting, slowed brain functions, and increased risk of cancers.

THMs can be filtered from our drinking and bathing water with reverse osmosis, as well as granular activated carbon, nanofiltraion and distillation.

While THMs are monitored in the public water supply they are still widely present, and the best way to protect your family from these chemicals is with a water treatment system capable of removing them from the water in your home.

Carbon filtration and reverse osmosis are effective ways to remove the majority of chlorine from your water, and even letting water sit out for a while before drinking can somewhat reduce the amount of chlorine it contains, though it’s a more time consuming and less reliable method.

Some public water filtration facilities have switched from using chlorine to disinfect water and are instead using chloramine, or chloramination, to reduce the formation of trihalomethanes. This is thought to be a safer alternative to avoid THMs produced from chlorine disinfection.

However, while now widely used, chloramines can produce nitrosamines which are suspected of being a human carcinogen. Nitrosamines are able to cross the placenta.

These are also problematic for hemodialysis patients because they’re able to enter the bloodstream through dialysis membranes. In cases where water containing chloramine has been used with dialysis, some patients have required transfusions to treat a resulting condition called hemolytic anemia.

They are also detrimental to fish and are able to permeate their gills, as well as reptiles, amphibians, and other animals able to absorb water directly into their bloodstream.

Chloramines are also potentially more corrosive to pipes, leading to metals such as copper or lead if present leaching into drinking water. It can also cause more rapid deterioration than chlorine in rubber items, such as the rubber parts of a toilet tank.

The corrosive effects of chloramines can be limited with pH control and other measures, but to filter it from your drinking and bathing water, a reverse osmosis filter is effective.

Haloacetic acids are another contaminant that can form from chlorine or chloramine treatment, including bromochloroacetic acid and other likely human carcinogens. They result from these disinfectants bonding with organic materials such as plant matter.

While disinfectants such as chlorine and chloramine serve a purpose to make public drinking water safer on its way to your home, removing them before drinking or showering is an option. Avoiding them altogether would be nearly impossible, and haloacetic acids are often present in sodas, fruit juices, and other food or drinks that contain water, as well as grocery or restaurant food that’s been rinsed or boiled.

According to the Institute of Medicine, 20% of our total water consumption comes from foods. Haloacetic acids may also be present in natural foods at low levels.

Of course chlorine is often present as a disinfectant in swimming pools and could be ingested while swimming or introduced into the body through dermal exposure or inhalation, though only ingestion is considered a major route of exposure to haloacetic acids from swimming pools.

Reverse osmosis is an effective way to filter both chlorine and chloramines from your household water.

Consult with a licensed plumber qualified to install professional water filtration systems if you need advice on the best system for your home, and to ensure your water is safely disinfected and filtered as needed at all points of use.

 

Forever Chemicals

Widespread in drinking water in the United States, these chemicals, known as Per- and Polyfluorinated substances (PFAS), are of concern. This class of chemicals take hundreds to thousands of years to break down in the environment and will persist in the body causing unknown health consequences.

Thousands of PFAS are being manufactured around the world. Six hundred known PFAS are currently used in non-stick cookware, cosmetics, stain resistant carpet and furniture treatments, paints, sealants, personal care products including many brands of dental floss, food packaging including microwave popcorn bags, pizza boxes, candy wrappers, takeout containers and more, foam from fire extinguishers, electronics, textiles, and countless other products in the United States and around the world.

It’s also present in many types of foods. Biosolids from fertilizer used on agricultural lands can contaminate ground and surface water, and landfills and hazardous waste sites also are a significant source of these forever chemicals. Due to the strength of the carbon-fluorine bond in these compounds, once in the environment, they continue to accumulate.

They’re found virtually everywhere on Earth, even in the deepest oceans.

These forever chemicals have been linked to testicular and other cancers, thyroid and liver problems, weight gain, ulcerative colitis, preeclampsia, reduced ability to fight infections, high cholesterol, and developmental effects such as low birth weight, accelerated puberty, behavioral problems and bone variations. They’ve also been linked to decreased fertility.

It’s not known what other detrimental effects to humans and other species we’ll discover in the future, but the EPA states that PFAS can cause health risks even at very low levels.

The EPA also states that PFAS in drinking water are of greater concern than PFAS in water used for bathing or washing dishes, since less are able to get into your body through your skin.

View a helpful, printable, PDF from the EPA explaining more about PFAS here:

https://www.epa.gov/system/files/documents/2023-10/final-virtual-pfas-explainer-508.pdf

 

It’s estimated that over 200 million Americans drink tap water that contains perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), two types of PFAS. The Centers for Disease Control and Prevention states that 99 percent of Americans have PFAS in their blood, including newborn babies.

If you use public water, you can contact your drinking water utility for information about what contaminants may be present and at what levels. If you use a private well, you can have your well water tested annually for safety.

 

 

The Environmental Working Group is a nonprofit, non-partisan organization that provides helpful information about PFAS and how they affect our bodies on their website.

View EWG’s interactive map showing drinking water and groundwater contamination in U.S. communities here:

https://www.ewg.org/interactive-maps/pfas_contamination/map/

 

More Information from EWG here:

https://www.ewg.org/interactive-maps/pfas_contamination/

 

The best way to protect yourself from exposure to PFAS in your drinking water is through a reverse osmosis filter at your tap, which is deemed more than 90 percent effective according to the EPA in removing a wide range of PFAS.

Many low-cost countertop pitchers can also be effective in reducing PFAS concentrations. Regardless of which filtration system you choose, routinely replacing the filter is imperative for filtration to work.

 

View a two minute video from EWG below comparing the effectiveness of low cost filter pitchers, although keep in mind these pitchers are primarily made of plastics, so you may want to transfer your filtered water into a better container for storage. Do your own research to be sure you’re not introducing more contaminants with your storage container.

“Getting ‘forever chemicals’ out of drinking water: EWG’s guide to PFAS water filters”

Video information from EWG: “EWG staff bought and used 10 different types of water filters, testing them in real homes using their water. EWG Senior Science Analyst Sydney Evans talks through the results.”

https://www.youtube.com/watch?v=z4d494nsOLI

 

Read about the results of the U.S. Geological Survey and PFAS here, which states that at least 45% of the nation’s tap water likely contains one or more PFAS:

https://www.usgs.gov/news/national-news-release/tap-water-study-detects-pfas-forever-chemicals-across-us

 

Radionuclides

Radionuclides such as uranium, radium and others are a greater concern for households with well water than for those households with publicly treated water, and can also be almost entirely removed with a reverse osmosis system.

Note that radon, different from radium, cannot be filtered out of our water with reverse osmosis. More on this below.

 

What reverse osmosis doesn’t remove:

Carbon Dioxide and Radon

Carbon dioxide is not a concern, but can easily pass right through the semi-permeable membrane of a reverse osmosis filter.

Redon is of greater concern since it’s a radioactive, cancer-causing gas that has no taste or smell to alert you of its presence. According to the Centers for Disease Control and Prevention, “30 to 1,800 deaths per year are attributed to radon from household water,” and radon is the second leading cause of lung cancer in the United States.

Radon gets into ground water as naturally occurring uranium, radium, or thorium in soil, rocks, or water break down. You’ve probably heard about the need to test radon gas coming into your home from the soil or bedrock through construction joints, gaps around service pipes or in suspended floors, drains, cracks in walls or floors, or sump pumps, but not everyone knows it can also get into your air from your water supply.

High levels of radon in the water supply is more common when the water source is a private well or a public water supply that uses groundwater (underground water) rather than surface water (such as a river, lake, or reservoir).

While public water is regularly tested (contact your utility for more information about testing and results), private wells must be tested by the homeowner.

When you use your household water to wash your hands, bathe, wash dishes or clothing, or any other time you’re exposed to household water, the water is disturbed and releases radon gas, if present, into the air. Over time, breathing radon in your household air in high levels can cause lung cancer.

Radon can be removed by aeration treatment which sprays or mixes air and water then uses an exhaust fan to vents the radon into the atmosphere before the water is used. It can also be removed with Granular activated carbon (GAC) treatment, which is filtering water through activated carbon filters.

NOTE: While GAC filters tend to be more affordable than aeration treatment systems, radioactivity from any radon present will collect on the filter, therefore disposing of the carbon may require professional handling if high radon levels are present or if the carbon has been in use for an extended time.

Regardless of which above treatment method you choose, the water must be treated at the point it enters your home. Under sink filtration will not remove radon from the rest of the water used in your home.

 

Always choose a reputable licensed plumber to install any water treatment products in your home. Improper advice and installation could introduce more contaminents instead of making your water safer!

 

Find more information about testing your home’s air for radon on the EPA’s website here:

“The Guide to Protecting Yourself and Your Family from Radon”

https://www.epa.gov/sites/default/files/2016-02/documents/2012_a_citizens_guide_to_radon.pdf

 

This PDF from the University of Arizona provides a lot of useful information:

“Radon in Drinking Water and Arizona Domestic Wells”

https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1798-2019.pdf

 

Find more information from the CDC about radon here, including a short video:

“Radon and Your Health”

https://www.cdc.gov/radon/features/reduce-radon.html

 

You can find a detailed study for data nerds like myself here:

https://ncbi.nlm.nih.gov/pmc/articles/PMC9975051/

 

 

Finding a State Certified Water Testing Laboratory Near You

If you have a private well, you can contact the Safe Drinking Water Hotline (1-800-426-4791) to find your local State laboratory certification office who can direct you to qualified laboratories to test your water.

 

Some Counties Offer Free and Low-Cost Water Testing

Find information about state-certified drinking water laboratories near you on the EPA website here:

https://www.epa.gov/dwlabcert/contact-information-certification-programs-and-certified-laboratories-drinking-water#state-labs

 

Here’s the direct link to a PDF list of state certified water testing laboratories:

https://www.epa.gov/system/files/documents/2023-03/state-cert-programs-certify-labs-to-conduct-drinking-water-analyses.pdf

 

If you’re planning to sell your house and have well water, a record of monitoring your water for safety can be a boost to your home’s value.

 

2024 Water Test Pricing Examples:

In 2024 in Indianapolis as an example, most residential water tests range from $10 to $200 as detailed below.

In Indianapolis, one testing site is The Indiana Department of Health Laboratory (IDOHL). For Indiana residents, the following PDF provides information about how to order a water test kit through Access Indiana and provides examples of the types of tests available from local laboratories, the prices for each, and the turnaround time:

https://www.in.gov/health/laboratories/files/Water-Test-Kit-Order-Frequently-Asked-Questions-FAQ.pdf

• Bacteria in Drinking Water – $10
• Bacteria in Swimming Pools – $15
• Fluoride – $10
• Nitrate – $10
• Metals Short Panel (Arsenic, Lead & Copper) – $20
• School Testing for Lead, Copper, and Arsenic – $25
• Radionuclides (Gross Alpha & Gross Beta, Radium-226 & Radium-228) – $100
• 11 Metals Mid Panel (Arsenic, Barium, Beryllium, Cadmium, Chromium, Copper, Lead, Manganese, Nickel, Selenium, Silver) – $80
• 21 Metals Long Panel (All metals in Mid Panel plus Hardness, Calcium, Magnesium, Aluminum, Boron, Iron, Lithium, Potassium, Sodium, Strontium, Zinc) – $150
• Indiana Pesticides – $150
• Volatile Compounds – $75
• Total Trihalomethane Volatiles (TTHM) – $75
• PFAS (Perfluorinated Compounds) – $200

 

Conclusion

Whole House Water Filter:

• Ideal for larger households and those with multiple water outlets.

• Best for addressing a broad range of contaminants.

• Cost may be higher initially but offers long-term savings.

Tap Water Filter:

• Ideal for smaller households or specific points of use.

• Best for targeting specific contaminants.

• Cost is lower initially but may require frequent replacements.

To make the best decision, consider testing your water quality first to understand the specific contaminants you need to address.

 

Always choose a reputable licensed plumber to install any water treatment products in your home. Improper advice and installation could introduce more contaminents instead of making your water safer!