Dear PT, > What I am interested in is how water that has been distilled can still > be producing contaminants? It was my understanding that once it was > distilled it is contaminant free.
People used to use double distilled water when it had to be absolutely as pure as possible. Nowadays, there are (big and expensive) systems of cartridges used in lab and industrial settings that produce extremely pure deionized water that is appropriate for those applications. For us, double distilled is the most approachable way to get to that level of purity... though you should ask yourself if you *really* need that purity or if it's overkill. Why wouldn't the first distillation cycle get everything? Well, to start with, we've already talked about tossing off the first bits of water from the distiller to get rid of any volatiles that came off with the water and remain dissolved in the distillate. Then we learned to leave behind the last of the water, rather than boiling it off completely. This means that the resevoir doesn't need to boil dry and get hotter in order for the temperature switch to automatically shut down the heater. That makes it easier to clean out, I'm sure, but *also* means that some of the higher boiling point contaminants don't get a chance to evaporate and join with the last of the condensate to contaminate the batch. Both of these methods allow you to capture the purest portion of the output stream. Then there's not filling it all the way, which avoids the obvious problem of boiling water *splashing* into the condenser. The thing is that all of these processes are continuous... All the volatiles don't come off at the same temperature or infinitely quickly, and all of the possible contaminants have a perhaps small, but finite and measurable evaporation rate at whatever temperature you're operating. So, the whole while the water is being evaporated, at least some traces of these other things are also making it across to the output. So a second cycle of distillation, just as carefully done as the first (and *without* the output filter! <grin>) will simply take those contaminant levels down by *another* factor of however many orders of magnitude they came down with the first cycle, or at least close. I hope that makes sense? Peace, Mike D. [Mike Devour, Citizen, Patriot, Libertarian] [mdev...@eskimo.com ] [Speaking only for myself... ] -- The Silver List is a moderated forum for discussing Colloidal Silver. Rules and Instructions: http://www.silverlist.org Unsubscribe: <mailto:silver-list-requ...@eskimo.com?subject=unsubscribe> Archives: http://www.mail-archive.com/silver-list@eskimo.com/maillist.html Off-Topic discussions: <mailto:silver-off-topic-l...@eskimo.com> List Owner: Mike Devour <mailto:mdev...@eskimo.com>
