[marki]

The problem with distillation process is that some ionic salts will always make their way into the distilate. You would have to repeat the process a number of times to be sure that you have removed most of the salts. Same goes when distiling alcohol. If you want to get rid of most the water it takes a few runs to get it out. De-mineralised means just that, no ionic salts although there will be some small traces. We used to use "pure water" when running PCR's on genetic material when I was at uni. This stuff had been run through reverse osmosis, resins, distilation and god knows what else. Costly stuff. IF I owned an open tube scope I would use de-mineralised over distilled because its the salts that leave marks.

Ciao Mark