It is all pretty confusing to me. There is so much contradictory rhetoric and few solid facts. As posted above, Christopher recommends distilled, under the belief that the only minerals our body can absorb comes from food sources. Schulze takes a more moderate stand in just recommending pure water. He only specifically states to use distilled water first thing in the morning and in herbal teas. So his definition of purity is vague. Chet Day and Joe Mercola have relatively recently come out against distilled water. Who is right. I don't know. My intuition tells me that if you don't have flouridated water and your water supply is fairly clean, a very high quality filter will give you water with minerals. If you have flouridated water, there are a couple of filters that claim to remove flouride, but I'm not totally convinced yet. I'd need to do more investigation. Another thought is to distill or RO water and remineralize with something like Trace Concentrate, a de-sodiumized Great Salt Lake mineral concentrate. If I understand correctly, that will neutralize the problems of disolved carbon dioxide acidifying the water. Shown below is a link to Mercola, with the Chet Day article on why he no longer recommends distilled water.