I've never had "yellow" colloidal silver reaction...

I like hooking up the batteries to themselves, sorry for my old-school battery clips approach. I will note, however, that I have never created "yellow" silver colloid as I hear from others using home-made and commercial rigs. I do get my silver electrodes from C.C. Silver & Gold in Phoenix, AZ.

The other commercial rig I had that never made "yellow" silver colloid was the State-of-the-Art Instruments Silver Pulser, http://www.sotainstruments.com/

The Silver Pulser administers microelectricity through the skin to kill blood-borne pathogens and uses the silver colloid jacks to kill gut bugs, all in the Beck Protocol of electrical and magnetic blood/lymph cleaning.