Re: pH keeps creeping up
Jakebear,
A daily 1.8 ppm FC loss in a 27,000 gallon pool is not at all unusual nor high. In fact, with the CYA as low as 22, the loss could readily be higher if your pool gets exposed to more direct sunlight. I used to think that running a pool at the lowest CYA you could while keeping the FC at the appropriate minimum level was the way to go, but recent analysis and experiments (starting around here in a thread in the TroubleFreePool forum) has me now believe that higher CYA protects chlorine more than the traditional industry chart would indicate. So maintaining a higher CYA with higher FC should actually result in a lower chlorine loss so I not only agree with dcfrey, but you could go even higher and probably see even more benefit (seems almost weird to give advice that is 180 degrees from what it used to be, but I can't argue with reality). The CYA to FC ratio should be around 8.6 as a target (or lower) which puts it in the middle of Ben's Min/Max columns and corresponds to the 0.05 ppm disinfecting chlorine level in this chart.
Of course, I've avoided your rising pH issue and we now need to tackle that. There is no question that the rain would lead to a LOT of pH rise, but it sounds like you may have been experiencing this rise even before the rain hit. Perhaps the TA level is higher than last year, or there is more wind, or something else is going on. I doubt very much that the manual vs. automatic chlorine injection has anything to do with it unless dcfrey is secretly adding base to your pool water / chlorine mixture. Seriously, I think the best thing to do is to significantly lower your TA since we know that will help a lot with the total amount of acid, though may not help as much with the quantity of pH rise. So, first lower your TA a lot -- to at least 70 via Ben's Lowering Your Alkalinity process and see if you notice an improvement. If you do, you could lower it even more down to 50. You should also try and target a higher pH such as 7.7 and see how long it takes to move up to 7.8-7.9. If you find the amount of acid per time reduced, but the rate of pH rise is still unacceptable, then you could add the 50 ppm Borates which should slow that rise down though won't change the amount of acid you need to add.
One step at a time -- try the lower TA first since it's not hard to do and is easy to change back if for some reason you felt you needed to.
Richard
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