I was surprised that my pH seem to rise dramatically over a couple weeks, after raising the chlorine due to high CYA. I was also trying to get rid of some algae. At the same time, I got the pool pump system working better with better flow, so the spillway for the spa started working. Now I am not sure if I am reading high pH due to higher FC, or it is due to more aeration from the spa spillway. Will you get a different reading for pH with a pool with high FC and low CYA, and a pool with high FC and high CYA. I am not sure if I should be adding acid or not.