I've had my pool for 4 years and this is the first time I've had trouble managing my PH. I only use liquid chlorine, muriatic acid and baking soda. So this the scenario I encounter weekly. My FCL is 1.6, PH is 8.0 and TA 80. I add 2 gallons of chlorine and 1 gallon of muriatic acid. Next day the levels are FCL 4.8, PH 7.5 and TA 63. 3 days later the FCL is back to 1.6, PH is 8.0 and TA is 63. I typically have to add 15 lbs of baking soda weekly to keep the TA around 80-90 while this is going on. Before this year my PH always stayed in the 7.5-7.6 range with only minimal muriatic acid. My CYA is currently 47. Thanks for any advice.