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Comment by nextos | Hacker News Reader

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.

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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.

Well, there are always traces from some heavy metals and excess of chlorine for example. I was thinking about a gravity or a reverse osmosis filter. Surprisingly some studies I've seen came up with very good figures in case of rather simple gravity filters.

According to Brita they remove chlorine and cadmium (a heavy metal), amount other things. [1]

As near as I can tell, "gravity filters" work on the same priciple as Brita filters [2].

[1] https://www.brita.com/why-brita/what-we-filter/ [2] http://www.phoenixwaterfilter.com.au/images/stories/phoenix/...

P.S. I have never worked for Brita and havent used their products in years, so please dont take my comments as shilling.

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?

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.

> I've used them for years, though the effect on taste might be a placebo

Personal anecdote that it may not be placebo:

I find the tap water where I live (Northern part of NL) pretty delicious. In fact I can hardly distinguish it from most non-carbonated bottled water, it's just clean with no particular flavour I would recognize (though maybe I'm used to it). When I visited the US (NY and New England area) I found the chlorine taste quite noticeable, also a slight dusty/earthy flavour (I didn't complain, and it was a hot summer).

However, one of the people we were staying with brought one of those plastic jug/caraffes with a built-in filter (probably charcoal), which she filled with tap water. I really didn't expect it to make much of a difference, because how was a tiny filter going to take chlorine molecules (not ions, right?) and that dusty flavour out of the water, that quickly, just by pouring through? (apparently I have no idea how these filters actually work, and a little voice in the back of my head dismissed it as some weird health fad thing)

Well, I was taught :-) I was pleasantly surprised when I found that the filtered water tasted "clean", pretty much just like it tastes back home. But since I really didn't expect it to taste much different than straight out of the tap, actually half-expecting the filter might make it a bit more "stale" (assuming it would mostly take out some of the CO2 and O2 gases), I doubt that could be placebo, wouldn't you agree?

On the other hand, placebo effect can be really weird, in your head, even if you really believe it's not affecting you, so I'm not going to presume there was no placebo going on. I also didn't think to try a double-blind test or something, instead happily enjoying the refreshing filtered water during a hot summer :-)

I filter tap water with replaceable brita filters.

Not because it tastes bad, but because tap water around here is hard as hell, cooking pasta once or twice with unfiltered water is sufficient to leave traces in the pan (and yes pans get washed), limescale starts building up in the kettle in a pair of days (though to be fair between coffee and tea the kettle runs 6~8 times a day). Brita filters is the only thing I've found yet which gives me a month between vinegar-rinsing of the kettle (and yes, the filter dies in ~a month, start letting shit through and limestale instantly starts building up in the kettle, it's a right pain in the ass)

Your question... surprised me.

I am from Brazil, here everyone filter their tap water.

Also my Startup associate is from France, and he claims in France this is also true.

As for what we use:

This is a classic: http://www.precolandia.com.br/images/product/279021A.JPG

Water filtered with those clay filters (the filter itself is made of carbon, not clay) somehow always feel fresh, sometimes on extremely hot days I can swear that despite having no active cooling, the water that comes out is cooler than the air.

Also this is common: http://www.decorandoimoveis.com/wp-content/gallery/filtro-de...

My mother has this one: http://mlb-s1-p.mlstatic.com/elemento-filtrante-filtro-agua-...

It is really good, but very expensive.

Water from unbaked clay filters feels fresh due to evaporative cooling [0]. Some of the water seeps through the walls and slowly evaporates, cooling the recipient. The magnitude of this effect depends on air humidity. This is the same principle behind a Botijo [1].

I don't know where in the country you're from, but here the water and sanitation department said the water is okay to drink from the tap. Very few if any people do it anyway, as everyone is used to filtered water. Maybe water quality wasn't as good in the past, or as reliable (it still isn't).

[0] https://en.wikipedia.org/wiki/Evaporative_cooler

[1] https://en.wikipedia.org/wiki/Botijo

Hum, you're associate is not right. I'm from France and I don't filter tap water (nor the majority of people I know). You do find people that do it, but I wouldn't say it's the majority.

At my home, I use a filtering faucet with a carbon filter (the same thing you see in those filtering pitchers, or some fish tank filters). Mid-tier refrigerators that produce chilled tap water frequently include this kind of filter.

I installed an ultraviolet sterilizer before the filter. This has no effect on the taste, but it does prevent most sorts of pathogen from colonizing the filter. This isn't generally an issue, but we felt like it made sense to add this when we installed the filter anyway.

At my office (same municipal water source), we have a very fancy reverse-osmosis filter. This is the same thing most of the bottled water companies use. I slightly prefer the taste of this water, but I think this is just because it's colder. The device is much more expensive initially ($200+, vs. $10 for one of the pitchers or around $50 for an under-sink carbon filter).

My family has a reverse osmosis filter and it tastes identical to bottled water despite the tap being extremely hard well water. Depending on how much water you drink, it should pay for itself in a couple months. I think ours was $250.

I'll second this. I can actually enjoy drinking water when it comes from my RO system.

does anyone filter tap water?

We do, via refrigerator filter, even though we have very good water in this area (from Mt. Hood).

Other areas of the country aren't so lucky. Sometimes municipal water may come from[1]:

   a sewage treatment plant's outlet 2 miles upstream

400,000 people got sick, 100 people died.

[1] https://en.wikipedia.org/wiki/1993_Milwaukee_Cryptosporidios...

I've always lived near the Great Lakes in the US, and in general have never felt the need to filter our tap water.

That said, I know others who do (either charcoal or reverse osmosis).

I have friends who live on the east coast and they claim their tap water is awful and they typically drink exclusively bottled water.

I filter mine just to remove some of the taste the pipes add. I'm not sure if you're looking for something fancy, but I use a basic Brita water filter. The best thing to make water taste better thought is to chill it in the fridge though.

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