Anode/cathode, distilled water pH, plastic scrubbers.

I know, distilled water is supposed to have a neutral pH. But some is steam distilled, and some is de-ionized with resin scrubbers, or using reverse osmosis. Steam distilled should be a neutral pH, but others, not sure which, can have an acid pH and give funky results when making silver colloid, like causing black oxidation and a bitter taste. Check the pH of your distilled water.

Making silver colloid is like the process used in plating metal. You creat a positive and a negative charge, an anode and cathode. The silver will come off one side only. And instead of depositing on metal, it is released in the water. Switch the polarity of the wires if you have the ability to do so to use up both wires evenly, as with the stateoftheartinstruments.com/SOTA Instruments rig.

Theoretically you want to only use plastic scrubbies on your silver electrodes--two wires consisting of an anode and a cathode--so there is no wild card contamination from mineral grits on sandpapers. But I cheat and use a very fine black emery paper, and scrub that off with a plastic dish scrubber. God bless!