Section 28(3)(ii) in Tamil Nadu Urban Local Bodies (Regulation and Monitoring of Swimming Pools) Rules, 2015
(ii)Where bromine is used as a disinfectant, a bromine residual shall be maintained between 2.0 and 8.0 ppm. as total bromine. A bromine residual of at least 4.0 ppm. shall be maintained when the pool water temperature exceeds 30o C.