Alright, my FC was .5 and my TC/CC was 3 this morning so for the first time ever, I've shocked my pool. Now, I've been told that the FC has to "hold" until morning. Does that mean it has to stay at shock numbers (I've got it up to about 15 right now)?? If so, how long will it take to go down enough to let the kids swim? and what is a safe number to let the kids swim?