UV systems have been by all accounts, a very effective means for treating chloramines ( along with proper ventilation, filtration, etc) in indoor pools. Commercial outdoor pools typically have very low levels of chloramines. With air circulation being a non-issue, how much can the Sun's UV rays account for the destruction of chloramines in outdoor pools? Probably impossible to quantified that. If chloramines are found to be elevated in an outdoor pool, could it be suggested that the sun is treatment itself?