3 tons wrote:
RO water is purified down to the level of the ion, thus in a well maintained multi-stage system (functioning membrane) can be considered mineral free...Consider this:
Water that has gone through a RO system two or more times is considered an absorbent (solvent) that is used in kidney dialysis machines..
Unless minerals have been reintroduced, RO water should not be used in copper plumbing or coffee makers having metallic parts because it pulls ions out of the metals...
That just isn't true, and you notice that it says two or more times. That means you'd have to have RO units in series. Now we had an industrial RO unit at one plant where I worked and it had multiple filters (membranes) it would produce water that was good enough to feed to Demineralizers to make high quality demineralized water but that was it. It did not make 'mineral free water'.
We made DI water of such good quality that people came from all around the county to get some, including the local major university. Our Demineralizers used distilled water as a feedstock and the units stood 20 feet high and 4 feet in diameter and there were four of them. And we had about 300,000 gallons stored in SS tanks at any time.
All this is pointless tho, RO water is good enough for limited use in his batteries.