Pool Oxidation-Reduction Potential (ORP)

Oxidation-Reduction Potential (ORP) is a measure of a pool's ability to oxidize contaminants and kill bacteria.

Understanding ORP

ORP measures the effectiveness of chlorine or other oxidizers in maintaining water sanitation. It is expressed in millivolts (mV), with higher values indicating stronger oxidizing power. Most pools should maintain an ORP level above 650 mV for effective disinfection.

Factors Affecting ORP

  • Chlorine Levels: More free chlorine increases ORP.
  • pH Balance: High pH lowers ORP, reducing chlorine efficiency.
  • Contaminants: Organic waste, ammonia, and metals lower ORP.

Related Terms

  • Free Chlorine (FC) – The active and available chlorine that sanitizes pool water.
  • pH – A measure of how acidic or basic the pool water is.
  • Shock Treatment – The process of adding high doses of chlorine or oxidizers to break down contaminants.

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