The water at swimming pools and family pools shall show an alkaline reaction at all times when the swimming pool is in use. When ever 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 to permit the entire bottom of the pool to be clearly visible from the walkways. (Ord. 1276, 1970)