Our research into the nonstick cookware industry led us to the importance of water filtration. Here we discuss why you should have a water filtration system and what your best--most comprehensive--options are. Read on to find out more about this extremely important topic.
Types of Water Filters at a Glance
This table lists the basic water filtration options. The products we link to are the best we've found in each category, though there are often several options to choose from.
Reverse osmosis and distillation are the most comprehensive types of filtering, by far, and we recommend RO for its ease of use and high capacity (though it's not without its drawbacks, so be sure to read our pros and cons list below). Our more detailed reviews below are on distillers and reverse osmosis.
If you go with a different filtering option--pitcher, gravity, faucet, etc.--be sure you get the model with the best filtration ratings, as they can vary quite a bit.
Water Filter Type/Example | Features | Drawbacks |
|---|---|---|
 | -Most effective: Can remove up to 99.9% of impurities -Usually installed under sink but can be whole-house or countertop too -Can have different stages or carbon filtration and add-ons (such as re-mineralization) | -Can take up a lot of space -Slows down water flow -Wastes a high ratio of water (up to 4:1 gal) -Removes minerals, which affects taste (can add back in) -Must change filters periodically -More expensive than other water filters |
Distillation  | -Countertop appliance run by electricity -Boils tap water to remove contaminants -Extremely effective method removes nearly all contaminants -Usually has a carbon filter as well | -Good for only small amounts of water/drinking water because of slow cycle time -Can take several hours to distill 1 gal of tap water -Some systems hard to clean -Charcoal filter requires periodic changing |
Undersink Filter (not RO) Clearly Filtered Triple Stage Kitchen Faucet Filtration System  | -Effectiveness and price varies -Won't remove minerals -Easy to install -Takes up less space than RO -No water waste as with RO | -Not as comprehensive as RO -Expensive -Must do your research to know what you're buying |
 | -Gravity filters water -No plastic parts -Can remove more than 200 contaminants, incl. lead, arsenic -Up to 6000gal filter life (3+yrs) -No water hookup or electricity -Can filter any water source, including lake and stream water -Travel models just as effective | -Slow (about 1 gal/hr) -Big -Filters are expensive (but last up to 3 yrs) -Extra filter needed for fluoride -Removes good minerals too -No NSF certification -Must be careful not to overfill |
Faucet Filter  | -Inexpensive -Easy to install -Some remove lead and chlorine but mostly used to improve taste -Brands vary: check specs | -Won't work with every faucet style (standard faucet only) -Filter life varies -Can get in the way of using sink -Must switch filter on/off -Reputation for cracking/not holding up |
Pitcher Filter  | -All remove odors and chlorine -Some remove lead and fluoride -Only a few remove other chemicals -Easy to use -Inexpensive | -Small volume @ 1-3 qts -Can be slow to fill (the more it removes, the slower it filters) |
About Water Testing (What You Need to Know)
The EPA does annual testing of every municipal water supply in the country. They mail a report annually by July 1 to let you know the state of your drinking water.
If you have a private well, it is your responsibility to test your own water. Most authorities recommend that you do this annually. This government (CDC) site explains the basic facts about well water testing. To find testing laboratories in your region, contact your state health department.
How important is it to get your water tested, or pay attention to the EPA results? Well, if you want to know what's in your water, it's a good start. You will learn about important contaminants such as lead, arsenic, and biological pathogens, all of which are important to remove from your water.
However, we at TRK take a different position on testing than most sites you'll find, which is that you should assume that your water contains contaminants you will want to remove. This is true even if your water looks clean and tastes good.
Here's why we believe this. The EPA tests for about 90 chemicals, which is a woefully small number compared to the number of chemicals that could be in your water. Furthermore, they have not added a new chemical to their testing regimen in more than 20 years. While they do have lists of what they call Unregulated Contaminants, some of which are monitored by public water authorities, there are no laws enforcing the cleanup or removal of them from your water. At the present time, this includes all the "forever chemicals" used in nonstick cookware manufacturing.
Private labs may test for more than 90 chemicals, but there is no lab anywhere in the world that tests for every possible contaminant that could be in your water.
It may seem alarmist to assume that there are untested-for chemicals in your water. However, after our dive into nonstick cookware (just one industry!), and what we learned about water regulation--or more accurately, the lack thereof--we think it is just good common sense.
And you don't need to live near manufacturing plants for your water to contain unknown chemicals. Toxins abound from agriculture, mining, landfills, and other sources that may surprise you. Many dangerous toxins, such as arsenic and uranium, even occur naturally in soil.
What Contaminants Are Tested For?
According to this EPA document called Drinking Water Regulations, the EPA tests for chemicals in several categories:
In total, this amounts to around 90 contaminants. Regional tests may vary slightly, as different water supplies can be exposed to different contaminants, but the total number remains about the same around the country.
The Nonstick Cookware Industry and PFAS
Our research into nonstick cookware led us to see how painfully inadequate this number is.
To put it into perspective, the PFAS group alone--the chemical family that contains PFOA and PTFE used in making nonstick cookware--contains more than 5,000 chemicals. The EPA has identified several hundred actually used in manufacturing in the United States, and it does not regulate any of them.
PFAS chemicals (perfluoroalkyl substances), have been linked to several illnesses, including some types of cancer and birth defects. PFAS are known as "forever chemicals" because of their pervasiveness in the environment: they do not break down naturally, so once they're out there, they're out there for a very, very long time.
PFOA, probably the best known PFAS, is no longer used in the US, but the horse is long since out of the barn: it was used from the 1950s up until it was officially phased out in 2015, PFOA has been detected in nearly every water supply in the United States and is estimated to be in the bloodstreams of about 95% of Americans.
(The nonstick cookware industry replaced PFOA with other chemicals in the PFAS family called GenX chemicals. These are associated with many of the same health concerns as PFOA, are also unregulated--and are now being found in water supplies around nonstick cookware factories.)
Though nonstick cookware is one of the most prolific users of these PFAS chemicals, it is far from the only one. They are used in hundreds of industrial processes, including textiles, food packaging, firefighting foam, and many more. So while it's good that PFOA is no longer used, "PFOA-free" may not mean all that much because manufacturers are simply using a different PFAS (and again, none of them are regulated).
The EPA has issued a Health Advisory for PFOA and PFOS--the two PFAS chemicals found in greatest amounts in our water--and they are slowly moving toward regulation of these chemicals, but PFAS are currently not tested for under the Safe Water Drinking Act. You can read more about PFAS regulation in the EPA document PFAS Laws and Regulations.
This is just one chemical family. Imagine how many more chemicals could be out there that aren't being monitored. Yes, it's possible that PFAS is the only chemical group that's escaped regulation, but it certainly isn't likely.
Even if the EPA and your local municipality claim your water is safe and clean, it's better to err on the side of caution.
Why Doesn't the EPA Test for More Chemicals?
We can only speculate on this, but the biggest reason is probably bureaucracy. Identifying dangerous chemicals can take years, then putting chemicals through the legislative process can take more years.
Also, many chemicals, including the PFAS used in the nonstick cookware industry, were already in use when the EPA was created in 1971, so they were "grandfathered" in as safe chemicals without any testing at all.
Additionally, there can be resistance from local municipalities, who would bear the brunt of the expense of enforcing regulations and cleaning up the water (although this probably falls under bureaucracy, as well).
Again, we don't know for sure, but these seem to be the reasons that the EPA hasn't added a new chemical to the water testing regulations in more than 20 years.
RO and Distillation: Filtration Vs. Purification
Our cookware research made us acutely aware of the possibility of unknown, unregulated contaminants in the US water supply. You may think you're safe if you have well water, but many ground water sources are polluted with all sorts of undesirable chemicals from agricultural runoff, mining industry by-products, pharmaceutical chemicals, and--yes--PFAS.
With only about 90 chemicals tested for, how can you possibly know if your water is safe to drink?
Our position is that you can't know. Not for sure.
Thus, our recommendation is to use the most comprehensive water filtration devices available. The two best options are 1) distillation, and 2) reverse osmosis.
Most water filtration systems use some type of carbon filter to purify water. Many use multiple carbon filters because different types of carbon remove different contaminants. If you go with anything other than a distiller or an RO system, it will almost certainly be a carbon/charcoal filter or a series of them.
Distillation and RO are different. In addition to filtering the water through carbon filters, they actually purify the water in ways that are superior to filtration alone.
Filtering is good--in some cases, very good--but purification removes pretty much every substance the water contains, leaving behind the purest H2O imaginable.
Purification is the most comprehensive way to treat your water. The only drawback is that purified water tends to have a flat taste because all the healthy minerals that make water taste good are also removed. Some RO systems add minerals back in, or you can do it yourself with a pinch of salt or trace mineral drops designed for this purpose.
Distillation
See the Megahome Countertop Water Distiller on Amazon
What It Is
From Wikipedia:
Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container.
What Distillation Removes
Distillation removes inorganic compounds, most microorganisms, and organic compounds with a higher boiling point than water.
This may not sound impressive, but it basically encompasses all contaminant found in water. Distillation results in extremely pure H2O.
Distillation Pros and Cons
Pros
Cons
The two biggest drawbacks of distillation are that it's slow and small. Most countertop distillers can do a gallon of water at a time, and it takes them about 5 hours to distill one gallon. Thus, distillation is best for individuals or couples, but probably won't be able to keep up with a family.
The collection containers can also be a problem. We picked the Megahome Distiller (pictured above) as our favorite primarily because of the collection container: it is designed to be easy to clean. Whatever model you decide to buy, be sure the interior of the collection container is reachable for easy cleaning, as they have a tendency to get slimy and smelly if you do not clean them regularly.
Reverse Osmosis (RO)
APEC ROES-50 5 Stage RO system
Waterdrop Tankless RO System
See the APEC ROES-50 5 Stage RO System (tank)
See the Waterdrop Tankless RO System (tankless, requires electricity)
What It Is
Reverse osmosis is a form of membrane filtration. With a pore size range of 0.0001 – 0.001 µm, it provides the finest separation available. It is used for desalination and purification because it filters out everything except water molecules.
What RO Removes
RO removes total dissolved solids (TDS), turbidity, asbestos, lead and other toxic heavy metals, radium, most dissolved organics, chlorinated pesticides, and most VOCs.
Most RO systems will remove 99.9% of contaminants in your water.
RO Pros and Cons
Pros
Cons
About the RO Options
RO systems can have several stages that each remove a different contaminant from your water. By the time the water gets to the reverse osmosis membrane, it's very clean. Then, the pass through the RO membrane leaves you with pretty much pure H2O molecules.
Each filter at each stage will require occasional changing, usually once a year or once every 2-3 years. Filters are the largest ongoing expense of having an RO filtration system, and you have to keep up with them to ensure your water is completely purified.
Tank: Most RO systems, like the iSpring 6-Stage system shown above, have an under sink tank that you connect to a special water supply (you can see the faucets that come with both systems in the images above). Tank systems work by water pressure and gravity and do not require electricity.
Tankless: Some RO systems, like the Waterdrop tankless RO system, filter the water as you use it, so no tank is required. However, these systems have a pump to provide water when you turn the tap on, so they have to be hooked up to electricity. Having no tank is nice, but requiring electricity makes this a harder system to install and also makes it dependent on a source of electrical power to work.
RO wastes a lot of water. For every gallon of clean water you get from your RO system, at least one gallon is flushed away as waste. This is an unfortunate by-product of an otherwise very efficient system. The tankless systems tend to waste less water, but again, you're dependent on electricity for your RO faucet to work.
Overall, we prefer the lower tech tank systems, even though they waste more water. They're easier to install, easier to use, and usually less expensive.
Unless you have extremely tight space under your sink, we recommend a tank system as the way to go.
Best Water Filters FAQs
Here are the answers to some common questions about water filtration.
How Does Water Filtration Work?
Most water filtration systems, including gravity, faucet, pitcher, bottle, and even some under-sink systems use a series of charcoal filters to purify water. There are different types of charcoal or carbon filters that remove different contaminants, so the more comprehensive systems have a number of stages of filtration. Good carbon/charcoal filtration can remove 200+ contaminants--but be sure the one you buy will removed the contaminants you're most concerned about.
Distillations and reverse osmosis go a step further and actually purify water--so distilled water and RO water are always going to be cleaner than filtered water alone. We recommend these systems as they are the most comprehensive.
Read more about carbon filters
Do You Really Need a Water Filtration System?
Yes.
Most water, even if it tastes fine, contains contaminants. For example, PFAS have been found in pretty much ever water supply on the planet, and in the bloodstream of more than 90% of Americans. Since the EPA only tests for about 90 contaminants, a clean water report may not mean all that much. You should use a comprehensive purification system like RO or distillation as it is is the only way to know for sure that your water is safe to drink.
What's the Best Water Filtration System?
Distillation is great for individuals and couples, but typically can't keep up with households of more than two people. For this reason, reverse osmosis is the best system for most people.
Is Activated Carbon a Good Water Filter?
Yes, activated carbon filters are used in most filtration systems and can remove more than 200 contaminants. However, they are not as comprehensive as distillation or reverse osmosis, which leave you with pretty much pure H2O molecules.
How Does UV Light Filter Water?
Ultraviolet light (UV) kills pathogens such as bacteria and viruses. It's fairly inexpensive and easy to use, but it does not remove other contaminants from your water.
What's the Easiest Water Filtration System to Install and Maintain?
Probably the easiest filtration system to use is a pitcher water filter or a gravity water filter: simply fill the containers and let gravity do its thing. Many of these can remove more than 200 contaminants.
If you want more purified water, however, you will have to go with an RO system or a distiller. Distillation is also very simple in that you fill the distillation container, turn it on, and allow it to drip pure H2O into the collection container. Unfortunately distillers are slow and can only make a few gallons of water a day.
RO systems require some knowledge of plumbing, and if you go with a tankless option, you also have to hook it up to an electrical source. However, they are nevertheless fairly easy to install, and once installed, you simply have to change the filters every 1-3 years (depending on the system, your water use, and other factors).
If you're handy, you can almost certainly install an RO system yourself. If not, you may want to hire a plumber to do it for you.
What Water Filtration System Is Best for Well Water?
This depends on the water, but if you want the most comprehensive purification, you should go with RO or distillation.
What's the Best Water Filtration System for Renters?
Most reverse osmosis systems are removable, so they are okay even if you're renting. A distiller is also a good choice especially if your household is just one or two people.
If you don't want to install an RO system and a distiller won't keep up with your drinking water needs, go with a comprehensive filtration system like the Big Berkey (available in different sizes, including travel size) or the Clearly Filtered Water Filter pitcher.
What Are the Worst Contaminants in Water?
We believe the worst contaminants are the ones you don't know about--which is why we recommend using the most comprehensive water purification system available, which is RO or distillation.
What is NSF Certification and Do You Need it on a Water Filter?
NSF certification ensures that the water filtration system you choose has been tested by an external party and is guaranteed to do what it says it will do. However, the lack of NSF certification does not necessarily mean the filter won't do what it says it will. Some companies, like the makers of the Big Berkey, use other independent testers because the NSF doesn't test for as many contaminants as they believe it should.
When you buy a water filtration product, it should have some sort of certification, but not being NSF-certified does not mean it won't work.
Read more about NSF certification
What's the Best Faucet Filtration Product?
We think it's the iSpring DF2-CHR Faucet Water Filter, which gets high marks from many independent reviewers and removes a large number of contaminants compared to most other faucet filters. However, faucet systems aren't the best option for a number of reasons. They don't remove as many contaminants as RO or distillation, they can be cumbersome to work around, they slow down your water flow considerably, and you have to remember to bypass them when you don't want filtered water--hot water can destroy the filter. They also have a tendency to break, probably because they're in the way and get jostled frequently.
What's the Best Water Filtration Pitcher?
We like the Clearly Filtered Water Filter Pitcher, which removes more than 200 contaminants. This is as comprehensive as the Berkey and many under-sink filtration devices, and is impressive for a pitcher filter. But once again, this is nowhere near as good as RO or distillation.
If you want ease of use, this is probably your best choice. But if you want fully purified water, a pitcher filter isn't going to cut it.
What's the Best Way to Make Purified Water Taste Better?
Most carbon filters will improve the taste of your water, so any inexpensive Brita faucet or pitcher filter should work. And if you are mostly concerned about taste, you may think a purification system like RO is no good because it removes the tasty minerals from the water, leaving it with a flat taste. This is true, but it's easy to work around by simply adding a pinch of salt to your purified water or buying mineral drops made for this purpose.
Is a Whole House Water Filter a Good Choice?
A whole-house filter can be a safer choice, but there are many factors to consider. Most contaminants in water do not enter the body through the skin, so filtering your drinking water is by far the most important option.
Whole house RO systems can cost several thousand dollars to install and they waste a lot of water. Other whole house systems use a charcoal filter system, and some merely soften the water without removing any contaminants at all. You have to do a lot of research if you're considering a whole-house filtration system.
Unless your water leaves stains or dries out your skin and hair (for example, because of too much chlorine), we recommend filtering only your drinking water.
Read more about whole-house water filters
Other Types of Water Filters (And Why We Don't Recommend Them)
If you don't want to invest in RO and a countertop distiller isn't going to provide enough drinking water for your household, you can get some protection from less expensive sources. None of these are going to be as comprehensive as distillation or reverse osmosis, but if you do your research and find the best available, you can be protected from more than 200 contaminants.
Activated Carbon
Most water filtration systems use carbon and/or charcoal filters including pitcher, faucet, gravity, and water bottle filters. Most are cheap and easy to use. In many cases, activated carbon is used in conjunction with other systems or other types of carbon filters. Most distillation and reverse osmosis systems have one or more stages of carbon filtration.
While carbon filters can remove a wide range of substances, including organic compounds (chlorine), volatile organic compounds (VOCs), heavy metals, pesticides and herbicides, trihalomethanes (THMs), and pharmaceuticals, they won't remove mineral, salts, fluoride, bacteria, or viruses.
So while most water filtration systems have at least one stage of carbon filtration, carbon filtration itself won't remove some potentially serious contaminants.
Pitcher Water Filter
Pitcher water filters are just that: water pitchers with a carbon-type filter on the top. You fill the pitcher, and gravity pulls water through the filter, producing cleaner, safer water.
There are hundreds of pitcher filters on the market that all work to varying degrees. Some, like the Clearly Filtered pitcher, can remove more than 230 contaminants including lead, mercury, fluoride, and PFAS. But at $85, it's not cheap--if you spend about twice that you can get a much more comprehensive under-sink RO system.
If you don't want to spend that, you can go with a standard Brita pitcher for under $30. It will improve the taste and smell, but it won't remove anywhere near as many contaminants as the Clearly Filtered.
Besides not being very comprehensive in what they can remove, pitcher filters have a couple of other drawbacks. They're slow to produce water, and they probably can't produce enough in a day for a family of four. While better than nothing, pitcher filters aren't the best choice if you want to be confident that your water is clean and safe.
Countertop Water Filter
Like other types of water filters, countertop filters can be a pitcher type with a larger reservoir, gravity fed like the Big Berkey (available in smaller sizes and able to purify any water source, so great for camping), or complete RO systems like the AquaTru system. They can be freestanding or plumbed in to your sink.
Gravity countertop systems, like pitcher filters (which are also a form of gravity filter), use a carbon filter.
Even if you're interested in removing just a few chemicals, we recommend buying the most comprehensive one you can afford. Which brings us back to RO systems: yes, they're more expensive, but they are ultimately the most comprehensive purification system you can buy--and the ones that go under the sink don't take up counter space.
We want to caution people about some controversy surrounding the Big Berkey: the produce is not NSF certified and some independent testers have found discrepancies in the company's claims. The New York Times Wirecutter has done an interesting article about the Berkey if you want to read more.
Faucet Water Filter
Faucet water filters attach right to the faucet. They are mediocre at removing contaminants, with this iSpring model being one of the most comprehensive.
Besides not filtering out a lot of contaminants, faucet filters can be a pain for a number of reasons. The big filter can get in the way of using the sink for other things. You also have to remember to switch from filtered to unfiltered, or you risk wasting the filter, which has a finite life span and needs to be changed every few months or so.
You also need to have a regular faucet or a faucet filter won't fit. Before buying a faucet filter, make very certain it will work with your setup. Many modern faucets are not designed for filters.
Finally, faucet filters just don't seem to last very long. They have a tendency to break, probably because they are in the way and constantly being bumped and shoved.
For these reasons, we do not recommend a faucet water filter.
Water Bottle Filters
Water bottle filters use some type activated carbon or charcoal. If you're filling your bottle from sources you're not sure about, a bottle filter can help remove some contaminants. But they will never be as comprehensive as RO or distillation.
Note that some filtered water bottles are designed to purify tap water and make it taste better, and some, like Life Straw, are designed to remove pathogens and make water safe for drinking (e.g., for camping).
Both will provide cleaner, tastier water, but the better option is to drink your own RO or distilled water.
About Whole House Water Filters
Aquasana whole-house carbon water filter.
Most contaminants in water won't enter your body through your skin, so drinking water is by far the most important water to filter in your home.
But if you want to be thorough and completely safe, you may want to consider a whole-house water filter.
A whole-house filter is installed at the point where all water enters your house, so all the water in your home, including showers, garden hoses, toilets, hot water heaters, and appliances (such as your refrigerator ice maker) will use filtered water.
While it's important you filter all the water you and your family ingest, a whole-house filter may not be necessary for non-drinking uses of water unless you have particularly high levels of chlorine in your water. Some well water also needs complete filtering for various reasons, from improving taste and color to removing toxins.
Whole-house water filters are a bigger topic that we're not going to cover here. There are several types that offer several degrees of filtering, just like other types of water filters, and you have to do your research.
If you want to read more about them, we suggest starting with the Bob Vila article about whole-house filters.
Final Thoughts on the Best Water Filters
Many people get a water filter because their water tastes or smells funny. But even clear, great tasting water can contain contaminants--and probably does. The EPA tests for about 90 contaminants, but there are literally thousands of others they don't test for, or regulate. Many of these are commonly used across dozens of industries, so they could easily be in your water supply.
For this reason, we recommend going with the most comprehensive water purification system you can. The two very best are distillation and reverse osmosis, with RO being the best option for most households as distillation is too slow to keep up with more than two people.
Our final thought is this: don't depend on the government to protect you. Take your health into your own hands and make sure you and your family members have safe, clean drinking water.
We are not experts on water filtration, so if you want to know more, we encourage you to do more research. There is a lot of good information out there.
Thanks for reading!
Help other people have safe, clean water too! Please share this article:
Thanks for the advice to get the most comprehensive water purification system you can afford. I just moved into a home, and lately, I've noticed that the water has been tasting funny. I want to make sure my family is safe from contaminants, so I'll make sure to get a water purification system.
Thanks for the comment! Glad the article was helpful.
Thanks for the info about water filters. My friend wants clean water for his home. I'll tell him to get water filters.
I agree. One major purpose of water purification is to provide clean drinking water. Water purification also meets the needs of medical, pharmacological, chemical, and industrial applications for clean and potable water.
After reading this insightful article about whole-house water filtration systems I've been contemplating installing one due to concerns about contaminants in my water supply and your point about most contaminants not entering the body through the skin is quite informative. Thanks for sharing this information which is worth noting for my households with specific needs and ensures the health and safety of me and my family.
I appreciate the mention of considerations like high chlorine levels and the need for complete filtering in well water. It's a reminder that water quality can vary, and tailored solutions might be necessary. The reference to the Bob Vila article on whole-house filters is a great suggestion for those looking to delve deeper into this topic.