If I'm not mistaken, isn't distilled water 'steam' that has been condensed? I don't know how many impurities can 'go up in steam', besides the volatile ones, but then, aren't they 'distilled' off? I have a whole house water purification system that uses the different layers of beads (had this for 15 years) that also has a membrane RO system at the kitchen sink (same one used in hospitals for intraveneous solutions), that also is connected to my ice maker. It goes down to 1/10,000 of a micron, and the water is so pure, the ice is totally clear, none of that foggy white ice. I have used nothing but this water in all 8 of my humidors, with no problems ...