Ain't that the truth!
A few years ago a buddy of mine purchased an RO system for his lab primarily to have clean water for his salt water aquarium, he brought me in and showed me this $1000 table top unit while I just shook my head in disbelief.
Of course he read "on the internet" how its the cleanest water blah blah blah and how it was the best way to get the water he needed to maintain his fish tank...where his fish poop and pee all day long into it.
I didn't have the heart to tell him it was way overkill and totally unnecessary then I asked him how long it took to refill his huge tank and he said "overnight". He changes the filters once every three months and sucks up the costs for filters four times a year. Totally wrong system for the job and not necessary but he loves it.
He had to come up with a secondary tank for the fish to live in while he cleans the tank and refills and the lack of minerals in the water from RO treatment he compensates by adding powders to the water which he then has to circulate and adjust before he re-introduces the fish. I didn't have the heart to ask how much the chemicals cost since he was so proud that he found a bulk supplier for them and buys it by the pound!
What could have been a three hour procedure turned into a two day affair...just to have fish poop in. He wonders why the fish get sick more often and seem so shocked after putting them back into the tank, his coral and plants don't do so well either and need constant replacement because they die. He seems confused because his test equipment says the water is perfect chemically...Ok!
He is a very smart guy who usually knows what he's doing but not in this case, I just smile and nod to avoid a confrontation especially since he went out of his way to not ask my advice...after all its only part of what I do for a living.
At any rate I caution anyone looking for clean drinking water to take a hard look at RO before committing to it, it strips many of those "things" out of the water that make it an essential source for basic elements that your body needs to sustain life. As an example if you were to drink large amounts WFI water (water for injection) which is as clean as you can get, it would make you sick because it lack the metals and elements your body requires to sustain life...it will literally strip your body of minerals and kill you.
We use RO/DI water for removing minerals stains and deposits from pharmaceutical grade glassware after cleaning as a final rinse since it is electrically charged and will strip minerals off a surface very effectively...not something you want to happen in your body is it. Depending on the efficiency of the RO unit and the condition of the filters the water that is output can approach DI water in quality.
Like washing your hands to prevent infection there is a point where more is not better.
