
Why Does Tap Water Go Stale Overnight? - LukeB_UK
http://www.wired.com/2015/08/big-question-tap-water-go-stale-overnight
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TillE
The article touches very briefly on many possible explanations without ever
coming to a conclusion.

But I'm fairly certain it's the one they mention towards the end: the
evaporation of oxygen and the development of carbonic acid. That's why putting
water in a closed bottle slows down the process.

~~~
dalke
I've not noticed 'stale' water, so I'm a bit confused about the topic.

If what you say is true, shouldn't places which use lake water, or places with
a cistern, have the same stale taste to their water? Or those who melt snow
for drinking water?

~~~
pixl97
You don't drink lake water without further processing... Or at least you
shouldn't if you want your insides to remain that way. Well water has an
enormous range of taste, wholly dependent on a number of factors, including
the soil/rock type that the well is sourced from.

~~~
dalke
While it's certainly possible to get water borne illnesses, the likelihood of
that happening is low. Otherwise humanity would have died out long ago.
Quoting from
[http://bwca.cc/tripplanning/waterfiltration.htm](http://bwca.cc/tripplanning/waterfiltration.htm)
:

> Thirty years ago, we didn't fret about lake-water microbes. We just drank
> the water straight or spiked it with iodine. Today, that is changed. Many of
> us grip our water filters and cautiously take a sip. In fact, Giardia and
> other water-borne pathogens often star in those scary mind-flicks we conjure
> from bears, bugs, and huge, wind-swept waves.

> Don't get me wrong. I'm not saying that six months of recurring diarrhea
> isn't something to ponder. Just don't panic if you swallow a mouthful of
> lake water. The Boundary Waters isn't a New York sewer. Much of the water is
> clean. The problem is, we can't distinguish the clean sources from the dirty
> ones.

> That's why I filter, boil, or chemically disinfect the water I use for
> drinking, washing dishes, and brushing my teeth. On the other hand, canoe-
> country author Michael Furtman has roamed the Boundary Waters for nearly 40
> years, and hasn't treated a drop and has never been sick. He's not alone.
> Quite a few Boundary Waters old-timers and wilderness guides drink the
> water. But they are careful about where they collect it.

In any case, my water filter for camping is only a ceramic filter. It doesn't
change the oxygen or CO2 levels. If TillE's proposal is correct, the output
after filtering should still be 'stale'.

What you said about well water is true, but my examples were structured to
avoid ground contamination. If you collect rainwater, and let it sit for a
day, does it taste 'stale'?

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reubenmorais
Solution: start mountain biking. You'll be drinking warm, dirty, old water
from old bottles and finding it delicious in no time.

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CarVac
I leave tap water in a carafe in my refrigerator overnight before drinking it,
and even that tastes dramatically different when warm than when fresh out of
the fridge.

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euroclydon
Most faucets have aerators. Flat water has a distinctly different texture that
aerated. For instance, if you're really thirsty, you can chug distilled water
(which seems to have much less dissolved gases) rapidly, but spring water will
not go down as smoothly.

~~~
ac29
Scientist note: Do not drink distilled water, at least not as a significant
portion of your water intake. Water contains clinically relevant amounts of
minerals that are important for health [1]. Fortunately, most "distilled
water" sold as drinking water actually has these minerals added back in.

On a related note, really dont drink deionized water (you can think of it as
ultra distilled, also the process does not necessarily involve distillation).
Aside from tasting extremely nasty (dont ask), sufficient quantities are
extremely dangerous. Fortunately it is expensive and generally only available
in labs.

[1]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/)

~~~
rahimnathwani
You say that most 'distilled water' sold as drinking water has minerals added
back in. Where do you get this information?

I live in China, where tap water is not considered safe to drink, and bottled
(or boiled) water is the norm. In my experience, most brands of drinking water
do not contain minerals. One of the premium brands (Watson's) actually has a
separate 'with minerals' version, with a blue label instead of their normal
green label.

Oh, and I've tested several brands of water with a portable TDS meter, and all
registered between 0% to 5% of the values yielded from tap water at my home
and my office.

~~~
Abraln
The problem is with "pure" H2O. Water is REALLY good at dissolving things,
which it does better if nothing is already dissolved in it. The warnings I
have received Are the drinking completely pure water will leach minerals out
of your stomach/intestines. There is a big difference then the "public"
version of pure and the laboratory grade version of pure water. No water found
in nature would be considered the latter.

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smoyer
I live in an area where water is drawn from aquifers within limestone deposits
- I actually like the "taste" of hard water over soft, but when I leave a
glass of water out for the night, I might also see flecks of calcium
precipitant.

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rancur
mine doesn't at all. ever. in fact i had some in a bottle behind my monitor
for a year and it was fine

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nextos
Incidental question, but does anyone filter tap water? If so, using what
technology?

My area has decent water, but there are some issues. I tried bottled mineral
water, which I found quite inconvenient and expensive. It's probably very
harmful to the environment too.

~~~
ac29
Charcoal based filters, like brita, or the ones built into higher end
refrigerators are cheap and effective. I've used them for years, though the
effect on taste might be a placebo, and the water in our area certainly isnt
unsafe.

Of course, it depends what "issues" your local water has.

~~~
hefty
I used to use Brita filters for a long time but one day I looked closely and
noticed tiny dark flakes in the water from what I assume was charcoal from the
filter. Using new filters still left the flakes in the water so I just stopped
using them altogether. Now I've been drinking straight tap water for ages. The
taste was noticeably different at first but the tap water is perfectly safe
where I live and it saves money.

I still wonder if it's normal for those charcoal flakes to pass through the
filter and into the drinking water, and do they pose any concern?

~~~
forgottenpass
_I still wonder if it 's normal for those charcoal flakes to pass through the
filter and into the drinking water, and do they pose any concern?_

Yes, no, and if you soak the filters beforehand as the instructions say, there
are less flakes.

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yousifa
Tap water also contains chlorine or chloramine which evaporates fairly quickly
(chlorine much quicker). That may affect the taste directly or indirectly by
allowing other bacteria to grow in the water.

~~~
yousifa
\+ water quality can change fairly quickly (eg. overnight) source: im a
founder of water quality monitoring company

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rorykoehler
The water in Berlin tastes better after sitting for some time.

