I have been working in a chlorine plant for the last 28 years. We use Potassium Iodide to test the amount of chlorine in a solution. The colour is very reddish brown if there is a lot of chlorine present. Otherwise the chlorine test strips should be able to tell you. But with the water supply chlorine levels should be below 3ppm, really not enough to be concerned about. Sodium sulphite is what we use get rid of chlorine in a solution, but that also would neutralise the chlorine dioxide, as I think most things would react with both chlorine and chlorine dioxide in a similar manner. If you are really concerned about the chlorine, run the bath water hot and wait. Because chlorine is a gas trapped in the water, so it should leech out over time as the water cools down. When cool enough to hop in then add your mms or chlorine dioxide solution. Remember that chlorine dioxide a gas entrapped in the water and will leech out as well.
God Bless
