Just emptied my 225 gallon hot tub yesterday, and cleaned it out with Ahhsome. Refilled it today but can't get the pH to level out. Started out, the TA was 160 and the pH was 8.7. Using pool math, and many adjustments using muriatic acid, the lowest reading I ever got was 7.6. Finally happy, I checked it half an hour later and found it was back up to 8.3 with the TA at 160. Tried once again to correct it - the last time the TA was 110 and the pH at 8.5. I thought maybe it was a glitch with the digital pH tester, so checked my tap water - I'm on a well - and it read 9. Then I rechecked the hot tub water with the Taylor kit and it was at the very high end. Lastly I used a test strip and got the same range. Any ideas??