Good day, I am looking for associates who are using a Crest cleaning line with an AXAREL emulsion tank. We are currently having a problem in the AXAREL emulsion (#2) tank when cleaning wave soldered assemblies with electroless plated Nickel heatsinks. As the pH in this tank drops, we believe RMA flux acids are building up in concentration and begin attacking the electroless nickel. The heatsinks are blackened by exposure to the low pH emulsion. Due to environmental constraints, we recirculate our emulsion and dump and replenish when the pH drops to 4.0 The attack on electroless nickel can occur at pH levels of 5.3 I am looking for options/suggestions on how to maintain pH controls and for people with similar equipment who are cleaning circuit card assemblies with this emulsion tank approach. Thanks in advance. Best regards Ken Devitt ITT Avionics Clifton, NJ 973-284-3880