Re: That is the problem with you guys, the FDA reported that many producers of Colloidal Silver had no silver at all.

Hi grizz

I'd be more than happy to share that information with you. In my own case, I use Current Regulating Diodes such as the one shown bellow to control the amount of current going through my circuits. As they are very easy to use and make quick work of meeting the target current(amperage) needed for a particular setup:

As for the circuit, the following simple diagram illustrates how these are wired into the circuit:

RE: Also which DC voltage do you consider optimal?

I've followed the going standard of 30v DC for most all of my own CS processing setups with very good success. That said, there is much to glean from the effects of voltage with respect to colloidal silver production. Such as; the dynamics of the voltage(effects) and current and its effects on processing. Though I'd add that such discussions albeit interesting, usually fall under the more advanced stages of CS productions methods. 

Hope this helps