Re: current control
I like using a potentiometer and the setup as it allows me to, after experimentation, to arrive at a resistance value that will prevent the solution from turning yellow. In starting from scratch for a home brew system, there are a lot of variables to consider. The most critical geometry of the system. How big are the electrodes? How far apart are they? How much water is in the container? The further apart the electrodes are, the higher the initial and final resistance of the water. How good is the distilled water were able to obtain? That will vary. I have found with a manual set up that it is best to start with as high a voltage as I can. For safety sake, this is limited to 48 V.
Initially, one would start with the potentiometer set at 0 ohms and monitoring the current using the 2 V meter across a one K resistor to read microamps. As the current gradually increased, I would increase the resistance on the potentiometer to keep the current below the amount that I decided was appropriate. Eventually, you come to the point of equilibrium where the current pretty much stays the same. If you have limited the current to a value low enough, you will then find that you can let the process continue for up to a day without particles forming large enough for the solution to turn yellow.
Now now you can simply leave the potentiometer in the same position. It will not take that much longer to get to that current level the next time you run a batch, less time than you would think.
I have found that I can achieve over 20 PPM ionic, clear and stable
Colloidal Silver by using this method. Here is a link showing the whole process.
https://www.atlasnova.com/csg-hg.pdf