ORP / COD Meters

ORP (Oxidation Reduction Potential) measures a water system’s relative state for gaining or losing electrons. ORP values are affected by all oxidizing and reducing agents, not just acids and bases that influence pH measurement. In practice, ORP measures the ability of a lake or river to break down waste products, like contaminants and organic matter. When the ORP value is high, there is lots of oxygen present in the water. 

COD (Chemical Oxygen Demand) is a measure of the total amount of oxygen required to chemically oxidize organic compounds in a water sample. In essence, COD indicates the level of organic pollutants, while ORP indicates the solution's ability to break down those pollutants.