I think part of the discussion here is also about distilled water and de-ionized water, which some people think are very similar, but as their names suggest are quite different. Simply, distilled water is evaporated water vapour that has been condensed, so in theory is just water, where de-ionized water has had ions removed, which is (a) not a natural state, (b), still contains 'other' contaminates.
My understand is NEVER use di0ionized water, but use distilled water, mine come from a de-humidifier.