I've kept the FC reading between 15 and 20 (closer to 20) for the past seven days. However, overnight my FC readings have dropped the following: Sun -5.5, Mon -5.5, Tue -5.5, Wed -5.5, Thu -5.5, Fri -8.5, Sat -3.5. I have also checked pH daily and it wants to drift up to 8.2 or higher. I've added Muriatic acid as recommended by Pool Calculator. The water is clear, each time I check CC it is 0 to .5. but I can't get the FC stabilized. Complete test readings this AM: pH8.2, TA 120, CH 200, CYA 45, FC 10, CC .5. I'm on my 125th 121 oz (8.25%) bottle of bleach. I believe in this system or I wouldn't be clearing KMart,Walmart, and Kroger out of Bleach at 2.67 to 4.00 a bottle. I've had to order a second chlorine test chemicals from TFT and unless I can stop the FC drop, will go through my 3rd this seasonA! If anyone has further advice, I'd appreciate it and thanks for bearing with me.