Is there harm if the kids swim in a fast set pool with 10 (high reading of chlorine ?What can happen ?


It is likely that the worse that would happen is mild skin and/or eye irritation. However, many test kits only read up to 10 ppm, so dilute a sample by 1/2 with fresh water and test again to make sure that the reading still isn't 10 ppm. If it is still 10 after the dilution step, then the actual value is more like 20 ppm (2 X 10 because you are diluting by 1/2).