Hi There, I have an Auto Pilot Total Control System that generates Chlorine and also has a pump that injects acid (from a small tank) into the pool. The system has sensors to test ORP and PH and then automatically makes adjustments on its own to balance the levels. For about 4 years everything was great, then I decided to refinish the pool with an Epoxy surface instead of resurfacing it with another layer of Marcite. After I did that, the Auto Pilot system has never needed to add acid to the pool (i.e. the PH has always been low). Now I always need to add Sodium Carbonate to increase the PH manually. I spoke with Robert at AquaCal (the company that makes the Auto Pilot) and he said he does not know why the PH "slowly falls" instead of "drifting up". I know it has something to do with the Epoxy Finish, but I am not a chemist. By the way, I asked him if the company could re-program (or "reverse") the system "logic" so that I could put "Sodium Carbonate" in the tank and then when the PH gets low, the system could then turn on the pump to rise the PH. Brilliant idea, but he said that the system is hardwired and cannot be "re-programed". So bottom line, Does anyone know what I can do to get the water in my epoxy pool to always need acid instead of needing Sodium Carbonate (i.e. for PH to drift up instead of down)? Any help would be much appreciated.