I finally opened my pool last weekend. It was late due to several cold snaps, then an extended vacation. I was pleasantly surprised that the water wasn't even cloudy even though the water temperature was about 70F. I still had FC=1.5 after adding ~30-40% new water.
Anyway, my initial levels were:
Haven't tested CYA yet, but was ~30 last year before partial drain and refill, so I'm assuming ~20.
I added a box of Borax and got PH=7.6.
I added 13 cups of 12.5% bleach. That should have put FC~17.5. I think I miscalculated, because I wanted FC~10 assuming CYA=20.
By the end of the day
FC=4.5 (this seemed like a huge drop)
I passed the overnight test (no FC drop). I'll test at lunch today to see if an excessive amount of FC is being burnt off by the sun. I know I need to test CYA accurately and add stabilizer. I'll target CYA~40.
What I don't know is if I should tackle my high TA. It was also this high last year, and I just ignored it. I think it has some relationship with PH, but don't know why I should care about TA in and of itself. If I do want to lower it, pool math says to lower PH to 7.0 and aerate to get PH back. Any estimates on how long aeration takes by simply pointing an outlet upward? I don't really want to run with low PH for too long with my heater.