liquid chlorine raising pH

[waterbear]

waterbear-
Thanks for your reply. My TA is kept between 70 and 100. I add about 25 gallons of 12.5 % NaClOH / month and about 20 gallons of HCL / month. 50 lbs of sodium bicarbonate is added about once every 5 weeks. That's all I ever add (except for calcium once in a blue moon) so it seems to me that the net change in pH for my pool when adding NaClO is significantly +

So every 5 weeks you are raising the TA by about 36 ppm (from 70 to a bit over 100, I assume)...As a suggestion only raise the TA to 80 ppm. I think you will find that your acid demand does decrease and if you are adding less acid you will not be 'eating up' TA as quickly. The amount of bleach you are adding is really immaterial here. What you are seeing is the effects of TA on acid demand.

What is your target pH? If you maintain it higher (7.6 to 7.8) you will actually see better pH stability since the lower the put pH the faster pH rises.