One very important thing to note about bromine to chlorine. As long as there is so much of a trace of bromine in the water then when you add chloriine it will be converted back in to bromine. So before you completely convert over to chlorine you need to make sure that you eliminate all bromine from the water. After that you can use the same kit to test bromine and chlorine. Nothing else really changes except you can add cya now to stabalize the chlorine in the water.