Cameronbs==Thanks for the comment. as you say, even steamers can deliver impurities if the initial water quality is bad. I work in a oil refinery(hence the handle) and see the insides of boilers that use ultra pure water because they make 1200 psig steam. The water will leave a residue and in cases we have a small contamination of "regular" tapwater, the boiler will quickly shut down due to tube pluggage. Some may ask how steam can have impurities. Its due to carryover or small droplet entrainment in the steam. Bottom line, the purer the water, the less deposits you will get.
