An embodiment of an apparatus for adjusting a distance between an electrode and a liquid includes a control circuit and a sense circuit. The control circuit is configured to couple an applied calibration signal to the electrode, and to cause a motor to position the electrode a distance from the liquid in response to a sense signal. And the sense circuit is configured to generate the sense signal in response to the applied calibration signal. For example, such an apparatus can be configured for use as part of a system for producing a stable solution of suspended silver. As silver-containing electrodes shorten over time, and as the level of solution changes over time, the apparatus can move the electrodes toward or away from the solution to maintain the respective distance between each electrode and the solution within a range that has been shown to produce a solution of suitable quality.