Why ORP Systems Fail - and How to Stop it

ORP controllers can overdose a pool to 30 mg/L of chlorine while showing a perfect reading. This book explains exactly why - and how to stop it happening.Oxidation-Reduction Potential control is one of the most widely installed and least understood technologies in recreational water management. Pool professionals learn to calibrate the equipment. Very few learn how ORP actually behaves inside a real, operating water body - and what it cannot tell you.This book changes that.Written by a practitioner with more than forty years of field experience across domestic, commercial, and public aquatic facilities, ORP Control in Real Pools covers the full operating environment: hydraulics, turnover, filtration, carbonate chemistry, pH behaviour, temperature, cyanuric acid, salt, secondary sanitisers, probe selection, probe fouling, dosing system design, bulk chemical storage, calibration, troubleshooting, and the legal responsibilities that come with getting it wrong.It does not treat ORP as a magic fix. It explains what ORP is actually measuring, why it responds the way it does, and where - in spas, spray pads, heavily aerated systems, and stabilised pools - it cannot be relied upon.You will learn:Why ORP reads correctly while the pool is dangerously over- or under-dosedHow pH, CO₂, cyanuric acid, and temperature each distort what the probe seesWhy stabilising pH is the first step to stabilising ORPHow to set up, commission, and troubleshoot ORP/pH systems in real conditionsWhat the industry teaches about ORP - and where that teaching breaks downHow to manage bulk chemical storage safely alongside automated dosing systemsYour legal obligations when an automated system causes harmThe technical content has been reviewed for accuracy by Richard A. Falk, whose work on chlorine speciation and redox behaviour is widely cited across the industry.This is a companion volume to Pool and Spa Leak Investigation: A Practical Guide for Trained Professionals, and is part of a series written for technicians, operators, facility managers, and regulators who work with real pools under real pressure.ORP is not unreliable - it is conditional. This book explains the conditions.