pH = 7.0
use test strips
?CYA level, it's not on the strips
talked to a pool contractor who said he's too far away but suggested a heat pump with a back up gas fired...then he just rambled off topic. I had a lot of trouble understanding him. I couldn't understand if he was talking about heating the air or the water with the heat pump. It just made me more confused. Eventually he suggested a titanium heat exchanger for a gas pool heater...off to more googling
Thanks for the comments
7.0 is acidic and pretty low pH. That's right there where metal will gradually corrode over the long term. Why wouldn't you maintain it at 7.5 or 7.6 which is closer to "nominal" pH for a pool?
EDIT: Here's what Hayward says isn't covered by their warranty:
"Leakage caused substantially or contributed to by corrosive pool water in an acid condition (pH below 7.2)"