My pool's pH is constantly rising. I've tried for a few years to figure out why this is happening, but at this point I've kind of given up for the time being. It's not new plaster, I don't have any water features, I've played with the jet directions, etc. For whatever reason, the pH is just going to rise.
If I knock the pH down to 7.5 or so with muriatic acid, it rises back up to around 7.8 pretty quickly, then the rise slows down, creeping up to 7.9 or 8.0. If I continue to let it go, it still rises, but much more slowly.
I'm therefore wondering if I should run the pool in this 7.8 to 8.0 region rather than constantly fighting to keep it down in the "recommended" 7.4 to 7.6 range, which requires a couple/few doses of acid every week. In other words, if I wait until the pool is fully 8.0 before adding acid, and then only bring it down to 7.8 or so, it will reduce both the cost and the time of adding MA all the time. What I'm unclear about is how "bad" this is. I know that chlorine is more effective at lower pH, but I don't have any feel for how much difference in Cl effectiveness is made by any given rise in pH. At 8.0, what happens? Just how poorly does the Cl perform? Will this be noticeably harder on our eyes? My CSI will be higher due to the higher pH, but I'm wondering if it might be an equitable trade-off to run it a bit high (in the "potential scaling" range) in order to greatly reduce acid usage.
I just don't have the point of reference needed to make an informed decision here.
Thanks for any feedback here,
This is a plaster pool, about 22K gallons, and I use only liquid Cl. My general specs at the moment (Taylor K-2006):
FC - 5
pH - 7.7
TA - 80 (drops as I add acid)
CYA - 40 (will be increasing to 50 to 60 for summer)
CH - 700
Salt - 1800
Temp - 70