Drinking pure H2O isn’t good for you. As far as I know it could even be deadly. But what if you had a pill with all the minerals usually dissolved in water and washed it down with a nice big glass of distilled water? Would it be more or less the same as drinking tap water? Or would you need more time to dissolve the minerals? What if you threw the pill into the H2O and stirred?
Or am I missing something entirely? I think someone on Lemmy even explained to me the other day what is so bad about distilled water. But I’m stupid today and forgot.
As I understand your neighbour wants to remove fluoride, can he get an under tap filter that only removes those types of chemicals? If not, why not simply buy mineral/spring water. Where I live it’s the same price.