(A) Chlorine disinfection in the form of sodium or calcium hypochlorite or other disinfectant approved by the State of Illinois department of health shall be applied daily either by hand or by mechanical feeder as frequently as needed to maintain a definite residual throughout the pool volume while the pool is in use, except that gaseous disinfection equipment shall not be permitted.
(B) Disinfection shall be carried on in such manner that the amount of excess or residual chlorine in all parts of the pool at all times when the pool is in use shall be not less than 1/10 parts per million or more than 6/10 parts per million. A sufficient number of daily tests for available chlorine shall be made by the pool owner, and a record kept of these tests to insure proper operation.
(C) The water at private residential swimming pools shall show an alkaline reaction at all times when the swimming pool is in use. Whenever alum or sulphate of alumina is used, frequent tests shall be made to insure that the water has an alkaline reaction. At all times when the pool is in use the water shall be sufficiently clear so that the bottom shall be visible from the abutting walkways.
('69 Code, § 6-149)