I see that you posted the TA and CH in an earlier post in this thread. Sorry I didn't catch that the first time. So it's not an unusually high TA. You didn't answer about aeration features such as waterfalls, spillovers, fountains, etc. -- do you have any of those running?

Other than the curing or aeration, I don't know what would cause your pH to rise so much. If it's curing, you should notice some rise in CH over time. Exactly what sort of chlorine tablets are you adding -- do you know what kind of chlorine it is (does it say something on the ingredients list like "Trichloro..." or "Cal-Hypo" or anything like that, and if so what does it say)?

Finally, what exactly does the can of pH Increaser say are its ingredients? Does it say "sodium bisulfate"?

Richard