What makes you think you have hard water after the softener? If you are using the TDS meter, that is the wrong piece of equipment to measure for softness. The TDS of soft water will be higher than hard water. Water softeners do not remove TDS. Take a sample of your soft water to your local water treatment company and ask them to test it or take a sample to Sears and they will test it for you. Or invest in a Hack 5B test kit.