Hi all. The latest is that I've recently shocked the pool over a period of about three days. Not 100% sure I needed to shock. I went ahead because (1) I knew it hadn't always been dosed appropriately (2) my son was saying it looked cloudy underwater though it was clear from my vantage point outside the pool (3) leaves, pollen, twigs are out of control, they fall as fast as I remove them. After shocking, the water looks more sparkly and the view of the bottom is sharper. So I conclude that it probably was in the early stages of developing algae before shocking.
My question is whether my pool size needs to be adjusted for proper bleach dosing. It almost certainly does, but I want to confirm with the experts here.
Pool calculator indicated that I should add 815 oz of bleach for a 23K pool. I was scared of such a high number and decided to add only 626 oz. After testing I found that the 626 oz of bleach resulted in overshooting the shock target of 28 ppm Cl (for a CYA of 70) by 2ppm (reading was 30 ppm Cl). So I decided that our pool is likely something like 17,500 gallons not 23,000. Is this about right?
One more thing -- Right before shocking I did a long overdue soaking and cleaning of our four cartridge filters - they were surprisingly dirty and slimy - using tsp and in some areas I found Qtips helped de-gunk the folds. When should this be repeated, end of May? I shocked mid April.