Would be willing to bet that if you use Caustic to maintain pH, you will split the emulsion quickly. Suggest using (diluted for easier pumping) Monoethanolamine, with pH meter/controller set to just slightly below pH of incoming cleaner. Also, have a funny idea that used cleaner, pH adjusted, may clean better than new stuff, at least until Rosin soaps build up to the point that they do not rinse well. And, incidently, this can be virtually completely avoided by rinsing in deionized water. Good luck Rudy Sedlak RD Chemical Company