Abstract: A washer apparatus (10) includes a washing chamber (W) with a plurality of spray nozzles (N) and a pump (P1) for circulating the washing fluid (F) through the spray nozzles (N) for cleaning the contents of the washing chamber (W). A pH sensor (20) contacts the washing fluid (F) and a digital pH controller (30) connected to the pH sensor (20) generates digital pH values of the fluid (F). An acid neutralizing system (80) and an alkaline neutralizing system (90) are provided for selectively injecting acid neutralizer and alkaline neutralizer into the reservoir (S, T), respectively. An electronic controller (12) controls the operation of the washer (10) and the acid and alkaline neutralizer injection systems (80, 90) in response to the pH of the washing fluid (F) as determined by the digital pH controller (30).