Today's update!
Last night at 9pm the FC was 20. This morning at 6:30am, it was 16, dropped 4 ppm, too much.
The added 1 1/2 gallons of Clorox at 6:30am and checked the FC at noon, it was 17. I added another 3 gallons at noon and it rained at 3:30pm. When it stopped at 4:30, I went out again...