Hi, I used Jacks Magic #2 (copper and scale stuff) to remove stains in my 16,000 gal gunite pool. They say use total chlorine readings because the stuff messes with FC readings. I did. After a month of no FC readings and plenty of TC, I became worried and called Jacks help line. I was instructed to keep adding small amounts of the 12% and free would begin showing up...not. Three weeks later, still no FC and TC going higher I called again. I got a better tech who said to shock at 10 times the now 17 ppm of combined chlorine. Looks like about 20 gallons of 12%.
My CYA is 30, TA 90, CH 380, No metal (I use super sequa-sol weekly for my well water). I know to lower ph to about 7.2. The pool is 80 degrees. Water clear, tiny bit of green algae in skimmer before a nice dose of poly 60.
Add a bottle of sequa sol and pour in 20 gallons 12% at night? I use the TF-100 test kit and thats alot of drops to insure 170 ppm. Do I have to maintain that level for a while?