PH going up again!

[waterbear]

Yes, your CYA is low, and does need to be raised, which you are working on.....and I'm willing to bet that Waterbear's going to tell you to drop the alk to around 80 ppm or so and see if that doesn't help slow the pH rise...

Janet

I was going to say 70!

More important, with a CompuPool unit you want the CYA at 100 ppm, particularly if you have one of the non reversing ones. This will minimize the cell on time (and the speed at which the cell scales) while maintaining the FC (keep it at 5 ppm or a bit higher with this CYA level). Minimizing the cell on time will mean less generation of hydrogen gas in the cell which means less aeration of the water which means less outgassing of CO2 which means slower pH rise. (Outgassing of CO2 is the main cause of pH rise in salt pools, assuming no new curing plaster.)

Lowering the TA to 70 ppm will also slow pH rise from outgassing.