A poster on the goldismoney2 forum says:
Most agree that 3x 9v batts is best, 27v near perfect for creating the smallest nano particles of silver.
There is no such thing as the “perfect voltage” for making colloidal silver. What we have here is a system consisting of a battery or a wall wart AC adapter (voltage) distilled water between the silver electrodes (resistance) and the resulting current (milliamps). It is essential to understand that the voltage and resistance factors determine the amount of current in this system. It is the current in any electrical system that does the actual work. In Michael Faraday’s theory of electrolysis, voltage and resistance are not mentioned. The number of ions created is a function only of the current.
The 27 volts issue is dealt with in the very first post of this thread. I would suggest a careful reading of the thread from the start.
I repeat it here:
Three factors will determine the quality of the colloidal silver that you make. The first is the water that you use. It must be distilled to a high degree of purity. You will need some way to check that the water you are using is pure enough. The distilled water that sold in grocery stores in 1-gallon containers will generally be good enough. You will still need some way to check it. That can be done with a conductivity meter or by some method included in the design and function of whatever generator we use.
The second factor is the purity of the silver that we use. We want silver ions and preferably no other metals. We want to make a solution containing silver ions, as they are proven to be of great benefit. Many other metals can do us great harm. We must take every precaution we can to avoid taking toxic metals into our bodies. That is why we use only 9999 silver wire and insist on a certificate of analysis showing the impurities that are present. In the case of the highest quality silver, the most significant contamination will be copper which is not bad in small amounts. That will be the case in silver that comes directly from silver ore. If you buy silver without an assay certificate, it could contain scraps from manufacturing facilities that are alloying silver with any number of other metals. So it’s not just a matter of it being 9999, but what is the nature of the additional .01%. When we make colloidal silver, the result is a liquid solution with silver in parts per million (PPM). It makes no sense to try to economize on this. If we consider making colloidal silver at a strength of 10 PPM, for example, 1 ounce of silver wire could make theoretically 100,000 ounces or 1500 gallons of colloidal silver.
The third factor is the amount of time that we allow the process. Hydrogen will appear at the cathode (the negatively charged electrode, where electrons enter the water), and oxygen will appear at the anode (the positively charged electrode). In the days of the 3 9 V battery and silver coins method, we would wait until we saw a cloud. That we were told were pieces of silver forming in the water and stopping the process soon after that. In reality, the cloud created by hydrogen and oxygen microbubbles and meant that the process was in a runaway mode. Disconnecting the batteries at that point would, if you were lucky, get you perhaps a five PPM colloidal silver solution. It would not keep its strength for very long as the larger particles would quickly collide with and absorb the silver ions. A few of us promoted the use of current limiting to prevent the runaway condition. Some of us noted that the higher resistance we used, the better results we obtained in both higher PPM and stability. Many of us tried every conceivable method of stirring to allow the use of a higher current to speed up the process. All of my efforts in this direction failed. I could not get around the fact that for a given surface area of silver anode only a certain amount of current was allowed. There is a region surrounding the anode called the Nernst diffusion area. That is a region that will only allow a specific density of ions to exist before they agglomerate into larger particles. So for those of you with your setups for making colloidal silver, try reducing the current and allowing more time and let us know the results.
It has been some 30 years since I began suggesting the use of current limiting and a laser pointer in making colloidal silver. Before that time, the accepted method was using two silver coins, three nine-volt batteries, and a dash of salt. A watchful eye to stop the process when it had a yellow tint was essential. The trick was to stop the process before the water turned into black gunk. At this time, a man who claimed he was a retired oncologist selling vitamin supplements introduced the use of a fish tank bubbler. That worked to the extent that it prevented the runaway condition that caused the three nine volts’ problems. Electricity cannot flow through an air bubble, so the current path was repeatedly interrupted by the flow of bubbles between the electrodes. This guy became very popular and sold many people a kind of subscription for vitamins and made some money. I understand that he was later arrested and jailed for mail fraud. This method is still prevalent as it does work, at least to the extent of preventing the rapid formation of black sludge. To give him credit, I think he also told people not to use salt. This method was not as quick as the three nine volts, which meant that it took more time, but people didn’t mind so much because they could always watch the bubbles.
There is a problem with this. As there is no current limiting device, i.e., “resistor” in the circuit, the current between bubbles will not be limited. The particles leaving the silver anode will be in relatively large chunks. The scattering effect of coherent light causes the laser line formed in the solution. The amount of light reflected is not directly proportional to the size of the particle. For instance, a particle 10 nm in size will only reflect 1/1000 the amount of light as a particle 100 nm in size. Therefore, using this method to determine when to stop the process will cause the process to end when a relatively small number of relatively large particles are in solution, which is just the opposite of what we want.
I hope everyone keeps experimenting and keeps an open mind on improving the process. Those of you who are using bubblers and have a TDS meter would do well to check whether or not the bubblers are adding oxygen to your water, yielding you a false indication of silver PPM. To do this, run your bubbler for the same length of time without silver. Take a reading of ppm. It is from carbon dioxide and oxygen.