I have an I/G vinyl 25K gal pool which had an algae bloom about 2 weeks ago. I treated it agressively with bleach & cal hypo. It cleared up within 3 days of treatment. Pool is crystal clear but FC readings have stayed steadily over 10 since 6/27, despite no addition of Cl since then. This is using test strips since the Pentair test kit I have doesn't test past 3ppm, although I have ordered a FAS-DPD test kit.

My CYA is between 100 and 150, so I wonder if the FC readings I am getting is really a reading of CC? Does CYA also stabilize chloramines? The pool doesn't have a strong chlorine smell, so maybe the high CYA has kept the FC at such a high level? Should I shock now or wait until the FAS-DPD test confirms a high CC?