I've mostly sought out distilled water for battery maintenance. The issue was always the risk of contaminates fouling the solution. Hard water usual contains calcium carbonates; calcium carbonates can react to battery acid and maybe precipitate out on the plates. Not good. At one time it was the suggested for use in contact solution, but don't know if that's true. If I wanted to mix something and not have an odd effect, like, maybe DIY aftershave, I'd look for distilled water.



The last time was for packing a wound. Wanted to make danged sure the water was sterile, and looked for a jug. Couldn't find it, but did find a jug of "Spring Water" that turned out to have come from a well tapped into the same aquifer we used for the farm deep well. That looked like it was purified and filtered enough, so we ended up using that. That was no guarantee that it was sterile, though. We would have probably had to find a medical supply house for that.



Potable water is usually a great unknown because you never precisely know what's in it. What are the minerals and in what concentrations? Unless you find somewhere that will test it, you don't really know. That holds for bottled water as well. Some labels say "Minerals for taste." What minerals? How much? Don't know. Sometimes it'll tell you it's ozonated or something like that, but there's still a good bit of unknowns. And yet, other than cases of outright contamination, either chemical or pathological, you seldom hear of someone dying from drinking water.



I don't really care. Like most of us, I've drank what came out of the tap with no worries at all. I've drank actual spring water from a spring, and distilled water once, and hard water and soft water and have lived to tell about it. It's true that distilled water has no minerals, but we don't know what's in the other water, either. You could deplete electrolytes and such by drinking only distilled water if you didn't get the necessary minerals elsewhere, but that holds true of anything we consume. Hard water has minerals, but look at the occurrence of kidney stones and water hardness. Soft water has stuff in it, too, and some of it might be troubling or maybe not.



The upshot is, we don't usually know what is and what isn't in the water we drink. I'm sure we have to compensate in our diet for a lot of extras and omissions in our water, and never give it any thought. If you look on the labels, a lot of bottled water will say "minerals added for taste." Nothing about adding it for health, unless you look into those "smart" waters, or whatever they're called.



As always, if anyone has any health concerns, the only reliable source of information is your doctor. Ask him or her about the water you drink.