When to change the ion exchange cartridge in your deionizer?

You should change the ion exchange cartridge in your deionizer when you notice a significant increase in conductivity levels of the treated water, indicating that the resin is no longer effectively removing ions. Additionally, if you observe a decrease in water quality or a change in pH, it's a sign that the cartridge may be exhausted. Regular testing of the output water, based on your specific usage and manufacturer's recommendations, will help determine the optimal replacement schedule.