My pool is using up too much chlorine through the course of the day so a shock was in order. I need to bring my FC level up to 20 and hold it there until my FC loss at night is less then 1ppm. So, last night I start the process, get the pool up to 22ppm at sunset, this morning it has dropped to 14ppm so I add another case of chlorox bringing it up to 23ppm =/-. When I get home from work my FC has dropped to 8ppm. How does one manage to keep the ppm above 20ppm and still have a job. Do I need to really load up to offset the drop? With it dropping back to 8, did I lose any progress I might have made putting me back to square 1?