It all depends on the manufacturer and model of PH controller and how your CO2 canister is controlled. If your CO2 injection kit is controlled by an electronic solenoid via a simple on/off AC outlet on a timer, I would say yes assuming the PH controller is designed with AC outlets that turn on/off on the PH level set points. On the other hand if your CO2 kit is just a manual turn on/off valve, a PH controller won't do anything for you.