I have a fair understanding of how to maintain a shock level in my own pool over a period of time. I am curious though to hear from the full time pool cleaning folks how they do it for some else's pool. I'm fairly certain that they don't drive back and return every six or twelve hours to keep the FC up. I'm sure they come across green swamps every day and i would like to know what methods they employ to fix the problems in as few visits possible and still stay profitable.