Free chlorine test strips green color 0-10ppm Range

Green color colorimetric plate for the test strip.

Free chlorine involves the amount of chlorine that’s able to sanitize contaminants, if used properly, free chlorine can kill most germs within a few minutes. CDC recommends pH 7.2–7.8 and a free chlorine concentration of at least 1 ppm in pools and at least 3 ppm in hot tubs/spas.