OK Bob, you got me. I know what a pot still is. I am from Georgia after all. But what do you mean by a Rectifying still? Googled it with no luck.

How much water do I need? Well I'm going to go with the 7 tray wash and that uses up quite a bit of water over time. Which is why I started looking into this. And, Kirk, I was told by numerous people that I should be mixing my alt. proc. chemicals and washing my prints in distilled water. I have to admit that I never worried about it with the standard silver based process. Is it really necessary? Good question.