Ok, I tested the setup today using distilled water + 2 Tablespoons of Celtic Sea Salt
I used a brand new white plastic dishpan, as the original has become stained. I wanted to remove it as a variable and see the color changes more clearly.
I heated the water in a slower-than-Christmas Microwave at first, but then finally gave up and boiled some of it on the stove in an 18/10 S/S pan to get it warmed up. The charger started right up and took off running with bubbles at the grater which was attached to the negative clip.
I had to re-use my one-and-only grater array though, and it was a little discolored (Can't get all the stuff off, but I scrub it anyway).
Duration of the bath was 30 minutes because I don't really want my feet sitting in that muck any longer :-).
The first difference I noticed using distilled water instead of hot tapwater was the rate of speed at which the color change began, and the fact that it first turned more pinkish-orange than orange, which was interesting.
The distilled water also may have actually wound up darker (Same color as a very dark Irish Setter) this time by the end of the bath. It hasn't totally settled out yet. The foot bath did have a lot more bubbly froth on top at the end than it has before.
I switched polarity of the stainless steel every 5 minutes approximately, by picking up the array by the top plastic, then slowly turning it in the water while keeping it submerged. I keep it submerged because it is just fascinating how very clearly the live signal is in that water, and it is *very* directional. It sweeps through that water like a beam that could be aimed at something. Interesting..
Still 15 minutes into the foot bath I can't see my feet anymore.
So all this color I am seeing in the used foot bath water is not coming from any part of the hotwater system in the house, because no part of it touched the foot bath water at any time today. That leaves only the cheese grater array, of which I only have one.
Someone may want to try this with distilled water and a second brand-new S/S array, and see if that changes things. It's the only possibility I can think of that remains.