I have a bromine 730 gallon in ground spa. I have an automatic acid feeder that also reads my pH and ORP. My autofeeder pH is reading anywhere from 6.9 to 7.2 but when I test with Taylor chemicals I am upon over 8. I added about 4 OZ of acids to the pool this morning. The chemical pH stayed about the same but the autofeeder reading dropped to 6.6. 5-6 months ago I cleaned the sensors on the autofeeder. This pH difference just started in the last couple of weeks. Any input would be greatly appreciated.