Thanks for the info. We have the chlorine up to 10 ppm or more. Our test vial only goes to 5 ppm. I know this, because we diluted the pool water with 1/2 distilled water and the vial still read 5 ppm. Can I dilute the pool water futher to show a higher level of chlorine, if it is present? How I would I dilute the water more? Could I use 1 part pool water to 2 parts distilled and then triple the reading on the Ch test vial?
Thanks, Web