I have learned to not pay too much attention to the ORP values based on everyone's feedback on here and a month of experience now... but during that time, the pH has been pretty much dead on accurate as compared to my test kit values. Up until today. We got 1-2" of rain from Arthur today. All of a sudden, the IntelliChem pH reading dropped from 7.5 to 6.5. I thought may be it was pulling water from the top of the pool (skimmers) and the rain water is acidic, so I changed it to pull from the main drain, and it still shows 6.7 a couple hours later. I tested with my test kit and it actually reads 7.8 (was 7.5 with test kit yesterday). I have not added any chemicals for the last couple days. Only SWG running. TA is still dead on at 80.
I am going to believe the test kit reading... although, after 2" of rain, I did expect the pH to be slightly lower... not 0.2 higher. But I'd liek to figure out why IC pH dropped by 1.0 instantaneously and has stayed near there for a few hours now.
I have attached the IntelliChem history graph... is there something specific that may have caused this? Or am I now going to have to lose confidence in the pH reading from IC also... meaning I really wasted $$$ on this. I don't have the pH canister hooked up yet, so no acid was dispensed... luckily... since it would have done so incorrectly and dropped my pH well below where it should be based on this false reading.
Edit: Also notice the ScreenLogic error on the graph below... IC reading was 6.5 at the drop and is 6.7 as I write this, but the graph makes it look like 6.9. The graph is frequently wrong, both in history and current values.