How long does it take flock to work ? I shocked my pool last night and got up this am and put the flock in the pool and let it run for 2 hours and shut it down like the lady at the pool store told me to. Its been 8 hours (pump is still off) and pool is still cloudy. I'm getting tired of the pool stores I think there selling me stuff that I dont need or telling me wrong. I ordered a tf100 last night and I'm going to start checking my own water and staying way from the pool stores advice lol