I've had my spa for two years now and have consistently struggled w/keeping the pH in the recommended range ... with a new fill it will be around 7.6, but over time it drifts up and stabilizes around 8-8.2. This is actually perfectly comfortable to soak in, but as I understand it not great for some of the components including my SWG system. With my most recent fill, about 6 weeks ago, my TA started in the 30-40 range and the pH was around 7.6 so I figured I'd leave the TA alone. Now it has drifted up to 50 and the pH is 7.8-8.0. The only thing I've done is add a bit of water (maybe an inch) to replace the water that evaporated off. This is a 420 gallon spa. I'm tempted to try to lower the TA back down to 40 to see if that will pull the pH back down. So my questions are, what is causing my TA to go up (I thought it was supposed to be stable), and is it a good idea to try to lower it to get my pH back into the recommended range?