Quote Originally Posted by jereece
Then something is definetly adding more to pH than the bleach. In 5 years, I have never seen this small of a net increase in pH. I have only used generic brand bleach (5.25 and 6%), but have used a number of different sources. All seem to have similar results. So I don't understand what it could be. I only add bleach and muriatic acid, then maybe adjust alkalinity once around mid-summer with baking soda.

Thanks again for the info.

Jim
.04/day is about .3/week and that seemed to be around what you were seeing. In your post #13 you said that the rise in pH was ".2 to .3 units per week" so aren't we consistent?

Does anyone out there know the pH of bleach? For 12.5% liquid chlorine, the pH of just sodium hypochlorite in water would be 10.6 but the actual pH is about 13 because of sodium hydroxide (caustic soda or lye) that is added since concentrated chlorine breaks down faster at the lower pH. So maybe bleach is more basic than I would have thought and that would explain a strong tendency towards increasing pH for anyone on the BBB system.

Richard