I'm Wirecutter's water-quality expert. I don't filter my water
161 comments
·June 7, 2025BugsJustFindMe
OptionOfT
Your filter system is not set up for water that is microbiologically unsafe to drink.
And if that filter setup also has an RO system your cost is more, as with RO you have a certain amount of rejection rate.
mousethatroared
I trust my municipality to give me microbiologically safe water.
Because I trust bleach, not my local water authority.
I certainly do not trust them to give me chemically clean water. So I have a $150 under-sink RO system.
bilsbie
Is there a chance it can get contaminated with bacteria? I worry about the water sitting in there.
tguvot
last time i made calculation, it was still cheaper than bottled water
teruakohatu
> Anyone who trusts their municipal water supply because of handwave regulations and reports needs to read that again.
A better approach is to decide whether your municipality meets or exceeds guidelines (the 85% that do).
I trust my city (in New Zealand), but there are other cities I wouldn’t because their water infrastructure is old and under funded, or because of known problems in the recent past.
donnachangstein
> and maintaining a dedicated three stage filter spout next to my kitchen faucet costs me approximately nothing
Calling bullshit on this one. I have one, it's positively wonderful, but the filters are expensive and per the manufacturer's recommendation you're supposed to change them all simultaneously. So when one times out, they all time out. This runs approximately $150 a year minimum depending on usage.
BugsJustFindMe
> This runs approximately $150 a year
$150 per YEAR at american prices is approximately nothing. That's a measly 41 cents a day.
People spend far far more than that on far far more frivolous things without thinking twice.
EA-3167
People spend an order of magnitude (and much more) on coffee every day, never mind smokers or drinkers who spend crazy amounts just to hurt themselves.
Not that I don't love and respect Wirecutter (I don't), but I'm on team "I like how my water tastes when it's filtered."
bernawil
> So when one times out, they all time out
Some units give you different fixed timespans for each. For that reason, I just use the Reverse Osmosis stage and ignore the rest. RO is the last step, and in theory it renders pure water meaning the only reason to have the previous ones is to pre-filter somewhat the water and extend the RO cartridge lifespan. Problem with that is, first, there's no way to gauge when each filter is spent. Second, they're priced the same anyway, so why even bother. Just go straight from tap to RO! Keep the post re-mineralization stage if you want.
tguvot
pre-filters typically have specified "capacity" in gallons. which is measurable. also if water is very dirty filters get clogged and pressure dropped. it's also measurable.
"post re-mineralization stage" is actually "ph adjustment".
kelnos
I suspect for most people posting here, $150 per year is "approximately nothing".
mousethatroared
What system are you using? My five stage filter system has me replace the charcoal filters once a year and the RO every... three? Maybe five?
But let's assume it costs you $150 a year. Thats less than $0.50 a day for drinking and cooking water. I doubt you could buy any significant amount of bottled water for fifty cents.
tguvot
filters are cheap if you don't use fancy branded system that came up with it's own filter that incompatible with anything else
an_aparallel
You generally want to avoid cheap filters as they apparently can be tainted with formaldehyde
dzhiurgis
Have you tested your filtered water in “ half a dozen times with different laboratories”?
zahlman
> three stage filter spout
... But does it remove the PFAs?
BugsJustFindMe
You can read the independent test data sheet: https://www.brondell.com/content/UC300_Coral_PDS.pdf
But if you want a full RO system, go for it. They cost only slightly more and just take up more room under the sink.
timr
I'm failing to see your point. If you think it helps -- whether because of taste or personal trust issues or something else -- then great, filter your water. You do you.
The article is clearly for someone who is otherwise on the fence and doesn't have those issues.
BugsJustFindMe
> I'm failing to see your point
That's weird because I'm pretty sure that my point is explicitly spelled out. But just in case, here it is again:
If your trust is based in municipal numbers or statements, you should be aware that municipal numbers and statements are not trustworthy because there's a lot of widespread decaying infrastructure (and coverup!) between where they test, what they make public, and where your water comes out of your faucet.
And if your trust is based on "Rah, rah, America!", you should know that 15% (!!) of water systems serving over 10k people have PFAS levels measured above what the EPA says is safe. (And if you don't think that 15% is a lot, holy smokes, that's nuts.)
So if you aren't testing your tap constantly then you have no idea what your water is like, no matter what the city says their water is like.
And if you are testing your taps constantly, it's less hassle and gives a better result to just filter your water instead.
The author says "I don't filter because I constantly test my taps and they're good each time." That's not the same at all as saying that filtering isn't a generally good idea, especially for anyone who isn't constantly testing their taps. The author ALSO says "a fuckton of you have more PFAS in your water than the EPA says is safe, just not me, lol". The author also chooses to ignore that their good water today may become bad tomorrow.
jay_kyburz
Do you test your water after its been through the filters? I'd have some concerns about putting my trust in some random filter company.
rufus_foreman
>> municipal numbers and statements are not trustworthy
The claims of the manufacturers of filters, of course, are completely trustworthy. If you aren't testing the capabilities of your filters constantly, this is fine.
cypherpunks01
A surprising amount of Americans refuse to drink tap water entirely, in their own suburban homes with quality municipal water, or anywhere else they travel, holding the opinion that plastic bottled water is safer and better. Of course bottled water is regulated far less than tap water, and contains an ungodly amount of microplastics from manufacturing and storage.
Under-sink RO systems seem pretty great to me, anywhere you live. With a small holding tank, municipal water pressure is enough to drive small RO cartridges, requiring no electrical power to run, and giving more than sufficient flow rate for all drinking water. I think the biggest downside is a few hundred dollars in initial setup, and cartridges every year or two. This seems safer than relying on the changing opinions of experts as to what amount of harmful chemicals are safe to drink.
BugsJustFindMe
> A surprising amount of Americans refuse to drink tap water entirely, in their own suburban homes with quality municipal water
It shouldn't be surprising that Americans might understand that their water might not actually be safe despite the municipal government saying it is. It took two whole years for administrators in Flint, Michigan to acknowledge their lead pipe crisis. Trust needs to be earned and maintained, and America is notoriously bad at maintaining critical public infrastructure.
n4r9
> America is notoriously bad at maintaining critical public infrastructure.
How does that compare with food safety in commercial products? That's the question.
jandrewrogers
The water in some parts of the US has natural chemistry that makes it unpleasant to drink even though it is safe. California urban areas are notorious for this, as an example. In principle you could remediate the water to make it taste good and remove any discoloration (also a thing in a few regions) with enough industrial processing but that would greatly increase the cost of already expensive tap water.
People who grew up in one of these areas are habituated into never drinking the tap water even if they move to a city with excellent tasting and very high quality tap water. I’ve lived in extreme examples of both.
You also see the opposite case, where someone who grew up with amazing tap water naively grabs a glass from the tap in north San Diego and has a “wtf is this” moment.
PlattypusRex
San Diego's tap water tastes truly awful. The first time I ever traveled to another city (Denver), I was forced to drink the tap water and could not believe how good it tasted.
jandrewrogers
San Diego has the worst tap water for drinking I have ever experienced in the US. When I lived there, pretty much everyone had a reverse osmosis system installed to make it drinkable.
Fortunately, I live in the Pacific Northwest currently, which generally has some of the best tasting water you’ll find anywhere. No one would dream of not drinking the tap water.
porphyra
Even if safe, municipal water where I live (San Jose, California) contains a ton of chlorine and is super hard, making it unpleasant to drink. In contrast, bottled water consistently tastes fine.
adastra22
San Jose water is absolute trash. There may not be (much) lead, but there are a host of other minerals and contaminants. It’s also a roll of the dice whether you’ll find Legionnaires' disease in your pipes.
I have a whole-house soft-water filter for general use, and for drinking/cooking get 5-gallon bottles filled with RO purified water from The Water Spring on Homestead in Santa Clara. The municipal source for RO water matters, and Santa Clara has the best utilities in the valley.
Stay safe out there.
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Barrin92
sorry if this is a stupid question because we don't have chlorinated water in Germany, but do people brew green tea or good coffee with tap water? Doesn't it taste god awful? One of the things which I remember from my holidays in Spain as a kid, which is one of the few countries which adds it here, is that the water tasted like pool water.
justincormack
Water is chlorinated in Germany [1]. There may be less as ozone may be used as primary disinfectant.
[1] https://www.lenntech.com/processes/disinfection/regulation-e...
mousethatroared
Its extremely unlikely that German water isn't chlorinated. Perhaps you are thinking about fluorinated?
Chlorine in water is actually fine and tasteless at the concentrations it reaches at the taps - it's basically extremely diluted stomach acid.
The problem is chloramines caused by chlorinated organics. These give water the swimming pool smell and are bad for you.
The solution is easy - reduce the organics in the water before chlorination, and oxygenate (aerate) the water before delivery. But systems can get overwhelmed by too much rain and runoff.
tomatotomato37
Yes, water quality matters a lot in coffee enthusiast land. They actually make little mineral packets that you add to a gallon of distilled water to get a "perfect" brewing water - I know since I actually use them for my espresso machine to fight scale buildup from my +10 grain tap water.
Note this excessiveness is really needed for espresso though; a regular Brita jug handles more tolerant methods of brewing perfectly well (and to be honest most people murder coffee enough that the water is the least of their concerns)
donnachangstein
> but do people brew green tea or good coffee with tap water?
I use filtered tap water (under-sink type) which removes most of it.
A lot of the higher end coffee makers like Keurig have built-in filter cartridges in the water tank.
Most commercial coffee maker setups I've seen (hard-plumbed) in offices have a filter attached to the plumbing behind the appliance.
Water can be safe/potable and taste terrible, and vice versa.
an_aparallel
My general experience in Australia when i talk about drinking RO water is that im looked at like a crazed madman who drinks "holy water"... So atleast hear i daresay its safe to say the average persons taste and smell must be piss poor
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shigawire
If you drink it all the time you are used to the taste. At least that's how it is for me
darth_avocado
One side effect of RO is vitamin B12 deficiency. And there is some debate around whether that is true or not, but anecdotally, I had developed a severe B12 deficiency to the point that one day out of the blue, I couldn’t move one of my legs. I freaked out and went to the ER, and it turns out, 1 B12 shot later, I went back to normal within minutes. The doctor hypothesized that I had developed a severe B12 deficiency because of RO water and that I supplement my food with B12 supplements. The regular intake of meat/eggs wasn’t sufficient to compensate for the lack of B12 absorption.
cinntaile
What's the mechanism here? Because it's not like there is B12 supplements in the water.
micromacrofoot
reverse osmosis removes minerals like cobalt, which are used for b12 production
if you only drink ro water it can creep up on you, but takes some time
mousethatroared
If water is giving you any nutrient in a significant manner, change your diet.
jandrewrogers
Some essential micronutrients such as arsenic are primarily sourced from water. You don’t need much so most natural sources contain enough. There is actually a valid concern that obsessive over-purification of drinking water can lead to deficiencies of some trace minerals.
an_aparallel
My RO system has a remineralisation cartridge. You def dont want to drink ph neutral water, it feels hard, and doesnt taste sweet.
kadushka
I drank only distilled water for 16 years. No supplements all that time, just regular food. No B12 deficiency or any other health issues.
more_corn
But did you pair it with pure grain alcohol as directed for maximal protection of your precious vital fluids?
unyttigfjelltol
Similar risks regarding removal of sulfate from public water supply, or via filtration.[1] Who knew! Some of us were relying on actual nutrients from the water all along. Pristine water was, and is, a challenge for this cohort.
mometsi
In the linked article, rybett@aol.com uses the CORREL function in an openoffice spreadsheet to determine a weak correlation between autism diagnoses and sulfur content in tap water in a few regions of New Jersey.
His other publications include a self-published amazon book titled Autism, Enzymes and the Brimstone Demons. [1]
[1] https://www.amazon.com/Autism-Enzymes-Brimstone-Demons-Trill...
bbarnett
Interesting.
I'm on a well, but with super hard water. So I have a water cooler, which I empty into a Brita pitcher, but just for drinking.
Just for the flavour.
I cook with my hard water though. Lots of stews and soups too, make bread, etc. So I suspect I get sufficiently mineralised as a result.
For context, I was boiling a large pot of water and got distracted by a call. Most of the water boiled away, well over a gallon. I was left with a solid white disk of calcium at the bottom. Also, when I broke it to get it out, it was super sharp, almost cut myself.
eesmith
The only papers I could find in Google Scholar about this connection all come from India, and does not seem strongly connected. The study at https://journals.lww.com/jfmpc/fulltext/2025/04000/prevalenc... , for example, says:
> While some studies have hypothesized that the use of RO water could contribute to vitamin B12 deficiency, no significant differences were observed in this study.[20] Symptoms of deficiency were not significantly associated with serum vitamin deficiency status. Only VDD was significantly associated with fatigue as a symptom. This discrepancy raises questions about the current normative values for vitamin B12 and vitamin D3 in the Indian population and suggests the need for further research.
A whole lot of people drink RO water. If it were a simple correlation, I would expect to see cases and papers from all across the world.
I also know there's a long history of false claims along the lines "distilled water sucks the minerals from your body", also called "hungry water". I first heard in the 1980s as a supposed reason for not using distilled water in a radiator. Or even commentary of it in the Carnivorous Plant FAQ at https://www.sarracenia.com/faq/faq3385.html .
Because of that long history, and the lack of a good mechanism for how it should work, I need a much higher level of evidence for a direct, causal connection.
mousethatroared
A surprising amount of Americans live in cities that cheaped out on the water infrastructure and found out their water had lead.
Like me.
Luckily, I am very unreasonably distrusting of government and never drank the stuff.
hollerith
In your second paragraph you seem to be describing carbon-block filtration. Particularly, the maintenance of an RO system consists of a lot more than just replacing cartridges every year or two.
margalabargala
Could you elaborate? I have an undersink RO filter. Maintenance consists of changing filters every year or two.
an_aparallel
You need to change filters as recommended, change o-rings, and bleach the fittings. Algae will develop on those. Thats pretty much it.
I wouldnt run bleach through the filters. The filter medium saturates, and any further use will just recontaminate water
tguvot
you need sterilize entire system periodically. and completely empty/refill tank once in a while
zahlman
> ... bottled water ... contains an ungodly amount of microplastics from manufacturing and storage.
Is it worse than the other groceries we can't readily get without them being wrapped in plastic? Or storing leftovers in plastic bags at home?
s0rce
My guess is yes, because they can more easily get into the liquid. Unless you are talking about other liquids like juices or canned foods, those I would expect are similar or vary depending on the type of plastic.
more_corn
Didn’t the Trump EPA roll back water quality rules for forever chemicals? Chemicals that accumulate over time and are known to cause organ failure?
If the federal rules allow unsafe levels of PFAs it’s reasonable to expect that municipal water companies adhere to said unsafe limits. So no we probably should not trust our municipal water supplies.
Maybe in countries that have functional governments that’s a safe bet.
StopDisinfo910
I think the writer is sidestepping the main issue most of the people who want to filter their water are thinking about. Sure, your tap water is within the federal limits for contaminants. The issue is that these limits are significantly too high for PFAS out of convenience for the water supplying side.
ghostly_s
Wirecutter "expert" doesn't hold much sway for me with the quality of their reviews these days.
Uehreka
I love this guy’s review of the Molekule air purifier where he rips it to shreds while detailing his methodology. If nothing else, I definitely trust this guy.
aprilthird2021
Wirecutter is just a worse version of Consumer Reports where they don't guarantee they aren't running ads and accepting money from the retailers whose products are featured in the media
fossuser
It's even worse than that - they have the same anti-tech political bent as the rest of the legacy tech press. Thankfully we have better options now.
righthand
Question: Is there some implied negative critique of Consumer Reports here? I rather enjoy their work and the fact they're reader funded, but I wouldn't be surprised if there's something I should be aware of that's not clear from it (the way they test or how they accept another type of money). I know they review too many cars (every issue lately features a car banner at the top of the cover).
bobxmax
If I need something I usually just buy what Wirecutters recommends and I'm rarely disappointed.
dbcooper
>Why you should trust me
Absolutely zero mention of qualifications. If you do not have a chemistry/chemical engineering degree, or something closely related then why would anyone want to bother with your verbose writing?
mihaaly
Knowing something well is not dependent on formal education. Helps quite some, but not being a must. And more importantly: not a guarantee!
sitzkrieg
ah yes, degrees. i only absorb information from qualified individuals with degrees.
timerol
> I hated my pitcher filter long before I knew I didn’t need it. It would clog up any time a bit of rusty water came through the pipes, which, in a 70-year-old building with cast-iron service lines, was often.
I'm a little confused that this is used as an argument against filtering water. I get that iron is not a particularly worrisome contaminant, but I still don't want the occasional "bit of rusty water" showing up in my glass
vsskanth
It's mostly for taste at this point, rather than safety. For a long time I used to drink right from the tap, now use a filter pitcher simply because it tastes better.
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Crye
does it taste better because of temperature, aeration?
torqueehmada
Not the person you asked, but the chlorine level is very high in my muni water so I like running it through a Britta charcoal filter. If I'm in a rush, tap is fine.
recursivedoubts
I'm a dude who doesn't care to run a chemical analysis of my municipal water every couple days. I filter my water.
s0rce
If you don't test it how do you know what filters are needed to remove the contaminants. You may be filtering out things that aren't there and not filtering the actually hazardous things in your water. Although you probably guess things like PFAS and microplastics which appear to be ubiquitous now.
mihaaly
Have you tested your filtered water - in various conditions - or you just trust it based on the words of others?
recursivedoubts
I just trust the carbon filters. Sorry.
lantry
This is hilarious. You don't trust your local government, which is accountable to you and is made up of people living right next to you (drinking the same water); but you DO trust a faceless, unaccountable corporation. I guess the corporation probably has better marketing!
mihaaly
Who told you to? : )
rufus_foreman
You just trust corporations.
I mean I trust corporations more than I trust the government, but 0.002 is more than 0.001.
You seem like a very trusting person.
knappe
I go back and forth on the issue. I read our local municipal water reports but then things like this happen https://www.vaildaily.com/news/climax-mine-can-now-release-h...
Denver water couldn't force the mine to continue cleanup of the molybdenum (because they're bankrupt) and instead raised the tolerable levels of molybdenum in Denver water. The same thing happened in 2017, 2010 and I'm certain before that. And then we have things like this https://www.cpr.org/2025/06/04/free-private-well-testing-ote...
Colorado has some serious issues with mine runoff and water contamination.
https://www.pagosasun.com/stories/the-day-the-river-turned-o...
calmbonsai
Wirecutter was bad before the NYT acquisition and now it's lot any/all remaining credibility.
Much like CNBC, it's completely "turned the corner" for me and I take their editorial as a negative signal.
In other words, definitely filter your water.
bobxmax
> Wirecutter was bad before the NYT acquisition
How so?
foresto
> It is also certified for Particulate Class 1, which is a surrogate for microplastics.
Based on a web search, it looks like Particulate Class 1 means particles in the 0.5 to 1 micron range. Several carbon block filters are rated at 0.5 µm, so I guess they're meant to handle those microplastics, but it leaves me wondering:
Do any smaller microplastics exist? Are they likely to be present in municipal water supplies?
All the filter cartridges that I've seen, and almost all the housings and tubes that hold them and the water, are made at least partly of plastic. Given that water typically sits in these filtration systems for hours or days at a time when the tap is closed, could it be that microplastics are leaching into the water from them?
t0bia_s
Our tap water has strong chlorine smell. Since we add a filter, chlorine smell is gone and water taste better. When I drink unfiltered water from my parents house, I immediately recognise it.
Money quote:
> readings of PFAS that exceed EPA limits have been found in just 8% of small public water systems (those that serve fewer than 10,000 people) and 15% of large ones
15%!
Anyone who trusts their municipal water supply because of *handwave* regulations and reports needs to read that again.
Even if my water were 100% pristine as the author's apparently is, which they only know for their own homes because they've tested it at their taps half a dozen times with different laboratories, my tap water still tastes awful, and maintaining a dedicated three stage filter spout next to my kitchen faucet costs me approximately nothing and provides substantially better tasting water. And I don't need to worry about whether I live in the next Flint, Michigan.
It took two whole years for administrators in Flint, Michigan to acknowledge their lead pipe crisis. What your treatment plant claims it does and what your municipal government claims your safety profile is do not matter one bit if you aren't constantly testing the water actually coming out of your taps.
I'd rather just filter my water. It's much less hassle and I get better tasting water as a nice bonus.