Trying to open and balance the pool this year has become a nightmare. After repeated shocking ,the free chlorine level still dissipates overnight . latest readings are TC 2.1 FC 0 PH 8.4 Alkality 130 Calcium hardness 225 CYA 80 . (done by a well respected pool store). The water is clear with no visible signs of algae growth. To try and figure out the problem without spending hundreds more dollars in chemicals Iam now using a 5 gal test bucket. My latest attempt to try to reach breakpoint in the test is adding 1 oz of 8.25% bleach in 5 gal of pool water, which should be the equivalent (If my reasoning is correct) of adding 42 gal of the 8.25% solution to my 27,000 gal pool. To my way of thinking, this should raise the FC level well over the point necessary to kill off whatever is eating the chlorine . After adding the liquid chlorine to the test container , the test strip showed dark purple, but FC was gone overnight. Any suggestions would certainly be appreciated