I have a new 450 gallon hot tub and have been measuring how much Bromine levels drop when not being influenced through the additions of tabs or concentrate. It looks like my hot tub loses about 10 or more ppm per day without anyone swimming in the tub. My typical use is to keep the tub at around 102 degrees with the cover in place. Is it normal to have a Bromine ppm decay in 24 hours of this amount? My hot tub does have Ozone and UV cleaners built in.