ORP (Oxidation Reduction Potential) is a measure of a water system’s capacity to either release or gain electrons in chemical reactions. ORP is measured in millivolts and indicates if a solution is oxidising or deoxidising. The higher the positive number the more oxidising the solution is and therefore a lower positive number or a negative number will denote that the solution is deoxidising and contains antioxidants. With the reduction of oxidizing chemicals such as chlorine the ORP levels will lower and therefore show that the water has more antioxidants.