It is my understanding that, drinking distilled water may not be recommended. Its not recommended indeed. Or maybe its not not recommended... Maybe not not indeed........ Anyway....

Well, apparently, in some places, they actually acquire distilled water from various sources (desalinization, atmospheric moisture, etc), and sell for people to drink.

My question is: What are the methods used to treat distilled water, such that it becomes more like the "tap water" we drink? (or, perhaps, drinkable/safer in the sense of the not-recommended-links (that is, assuming such links are true ofc)).

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    $\begingroup$ Drinking distilled water in the course of consuming a normal diet is harmless. Your "not not" links are correct. That said, I'm voting to close b/c personal health questions are off-topic for the site. $\endgroup$ – hBy2Py Dec 5 '16 at 3:04
  • $\begingroup$ @hBy2Py I don't think this is personal health. I was just elaborating in the motivation of the question. I was very clear in section "My questions are" how to "treat" distilled water to make it be more like tap water. For the record, I don't think distilled water. Never did. $\endgroup$ – Physicist137 Dec 5 '16 at 3:06
  • $\begingroup$ I think a better question is why isn't it drinkable? And the answer is that it's essentially free of electrolytes. If you drink a lot of distilled water, you'll start leaching electrolytes from your body (pure dilution effect). In principle, you can just add some ions to it so that it's less of an osmotic strain on your body when you drink it. $\endgroup$ – Zhe Dec 5 '16 at 3:13
  • $\begingroup$ Phys, your exact wording, except for your parenthetical, is "such that it becomes drinkable" and "such that it can become fully drinkable." Those read as health questions to me, so w/o edits to the question my close vote stands. $\endgroup$ – hBy2Py Dec 5 '16 at 3:15
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    $\begingroup$ I do not see why this should be closed as a "medical" question. The OP is refering to the actual use of desalinated seawater, ans asks how this works. (I reworded the question slighly to make this more clear.) $\endgroup$ – Karl Dec 6 '16 at 10:08

The content of mineralic ions in tap water is usually rather small compared to the amount that you take in with your daily food. Especially Calcium content varies wildly between sources, and nobody recommends calcium supplements in cities with soft, low calcium content water.

The common DI water you have from a tap in a laboratory building or buy in the supermarket is not safe for drinking, firstly and mostly because it is not tested. But who would want to drink it anyway? It is more expensive, often has a taste that varies between lame and slighly foul, and you do usually have a regular drinking water tap to use instead.

The only way you could run into problems is when you have little food, drink a lot (hot environment), and have nothing to drink but distilled/rain water. On the other hand even well water likely has not enough sodium to balance what you loose through sweating.

To answer your question: A big problem with distilled water is its corrosiveness to common household tubing. Regular tap water coats everything in a layer of calcium carbonate, which makes even lead pipes relatively safe. In a standard copper pipe, DI water will first slowly dissolve the oxide layer, and then a lot of electrolytic corrosion will take place.

So, to use distilled water as tap water, you either have to make everything out of PE (doesn't really work if you want hot water), or add calcium carbonate. I believe this is what's done in areas where desalinated water is fed into the communal water supply. You just have to mix in some amount of local well water.

  • $\begingroup$ If you were to pipe distilled water, like for a city, then the corrosiveness is a very interesting point. $\endgroup$ – MaxW Dec 6 '16 at 0:12
  • $\begingroup$ Some municipal supplies (like, from glacier melt) find that adding some mineral content is a good idea, it reduces corrosion of iron pipe. $\endgroup$ – Whit3rd Dec 9 '16 at 4:12

There are several ways to make distilled water safe to drink.

(1) Pour it in a glass.

But my favorite is:

(2) Freeze the distilled water into ice cubes. Fill glass with ice cubes and add a shot of vodka to kill any remaining germs ;-) Then fill with tonic water and add a twist of lime. After you drink the mixed drink, then left the ice melt. The resulting water will be safe to drink.

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    $\begingroup$ While this is funny answer, I have a feeling OP was asking seriously. $\endgroup$ – Mithoron Dec 5 '16 at 13:28
  • $\begingroup$ Another highly scientific possibility, rather 1950ies-stlye : en.wikipedia.org/wiki/Irradiation#Sterilization ;-) $\endgroup$ – Karl Dec 5 '16 at 13:39
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    $\begingroup$ While working in a large industrial lab that delivered distilled water to your lab for free, we used it to make coffee - never had to de-scale the machine. And the coffee tasted pretty good - perhaps it really leached good stuff out of the coffee grounds... $\endgroup$ – Jon Custer Dec 5 '16 at 14:50

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