After I opened up the pool I measured 0 FC. I have it 1.5 gal of 10% bleach and fc came up to 2.2 ppm. I added another half gallon and retested around 5:00 pm and it's back down to zero. I also added 2 gal of liquid stabilizer the day I opened (3 days ago) since there was almost no CyA. So my CyA is up to 35, pH is 7.3, TA=150, CH=470. How does CyA affect how much chlorine you need? The calculator says a gallon of 10% bleach should raise fc to 4.2. But I kind of doubt that. Pool is 24k gal. How much should I put in tonight. Big pool party tomorrow.