Some "High voltage" [HVAC] people claim that distilled water will not conduct electricity and think they must use high voltage [up to 20,000 volts] to 'jump the gap'. Some low voltage people think that adding an electrolyte such as salt is necessary. Theoretically, they are correct. In actuality, they are not.

Note that one or two HVAC generators use an entirely different setup where a arc is produced, not in the water, but above it. [Electrosputtering?] I hear that process makes a fine CS if an inert gas blanket is used to prevent the formation of silver nitrates but the generator is very expensive and could be deadly to operate. [No one sells those to the public..too dangerous]

Controlling the current is done by automatically dropping voltage as the conductivity of the water goes up with the additon of ionic componants.

Current controls ion emission rate [Voltage controls ion velocity through the water ]

At the surface of the electrodes there is the "Nernst Diffusion Layer" which if overloaded with too high an emission rate, creates a high concentration zone where particles will form in the over saturated zone.

Keeping the "current density" of the electrodes down by tailoring current to electrode surface area, helps prevent oversaturation, reducing the size of the particles that do form and reducing the number of particles that form... there.

Low voltage, low amperage works. Even my engineer was surprised.