I use only distilled water and a pair of silver rods, a 24v dc wall wart, a quart jar, and a device that detects particles in the water down to .0001 PPM. When that device shows me .12 PPM and the water is a nice beer color it's ready. Usually takes only 4-5 hours. Adding salt would only serve to run the batteries down faster than need be. The silver particles can only be dissolved into the water so fast.
And FWIW captcha is fucked up!