They may ask you to add salt, heat the water, throw the solution out if it becomes muddy and start over, run the unit for short periods of time only and other requirements. All the variables are accounted for automatically. If the water is warm, the initial constant current will be reached a bit sooner than if cold water was used and timing may start a bit earlier. The water temperature will not control timing or strength of the solution once the target current is reached. Target current is low, so it takes very little time before the colloidal particles are being formed.
Salt is unnecessary and is a detriment to proper operation.
It will produce silver chloride which is a silver salt. We are looking for the metallic silver particles and ionic silver only. A constant current generator will make ONLY electrically charged metallic and ionic particles and it does NOT need additives to start the process. Proper timing is necessary to produce the quantity of silver in solution but it is NOT necessary to stop the current flow after a short period of time as most units require. Using those battery powered units, which are constant voltage generators are the equivalent of driving an automobile with the gas pedal stuck to the floor.