Actually, your TA is ok at 110. Go ahead and shock. Try and test a couple or three times a day and each time raise it back up to shock level, which for a pool with cya of 40 would be 15 ppm. When you CC is less than 0.5 (ideally 0) and your chlorine level isn't decreasing more than 1 ppm overnight, and the water is clear, then you can let the cl drift back down. But, with a cya of 40, you need to maintain the cl between 3 and 6 all the time.