Hey, shocked the pool due to some visible green algae behind the ladder. All other symptoms were perfect including a clean filter.
Using the pool calculator and with a residual FC level of 2.5 ppm, I added 1 lb of 65% cal-hypo (CH = 250), and 75 oz of 12.5% NaOCl to raise the FC to >16 ppm.
1.) The water became very cloudy after adding the cal-hypo.
2.) The FC level went higher than calculated to 19 ppm
3.) The next morning the water was sparkling clear but some white sediment on the floor and the DE filter pressure rose 9 psi and flow was decreased.
4.) After the overnight everything else is great:
FC = 18.5
OCLT = .5
CC = <.5
pH = 7.6
TA = 120
CH = 250
CYA = 45