So now should I up the voltage to 50 volts or 60 volts for each production run? How do you calculate run times with colloidal gold?
Well you can if you want.
You cannot calculate a run time like you can for silver. The reason is that there are several electrolysis processes going on at the same time, and there is no way to tell how much current is being used for each process. IE: You are electrolyzing the citrate which does not contribute to making gold chloride, you are electrolyzing salt which is making gold chloride, but also sodium hydroxide, hydrogen and oxygen. So you just have to gauge by the color.
If you actually look at the the stoichiometry, there is almost 10 times as much salt in my formula as would be needed to make 50 ppm gold. Without this huge overage, the electrolysis does not favor the production of gold chloride, and it takes a very long time to get any significant amount of colloidal gold. Personally I wouldn't mind the time required, but I do mind the fact that it has to be hot which means dealing with the evaporation loss, and the electricity it requires for the temperature.