I understand the need to shock a spa when the water becomes cloudy or another adverse condition exists but I don't understand why you must shock the spa right after a fresh fill. If I am able to start with 4-5ppm Bromine after balancing and building up a Bromide reserve, why is it necessary to shock up to 20ppm? If I do that, how long would it take for the levels to come down to the 4-5ppm I want to keep the spa at? At what level of Bromine would you not want to enter the spa?
In a Bromine tub, how long do you need to run the filter cycle every 24-hours?