The PoolWarden is a water chemistry control system with capabilities to control the pH, sanitizer, and temperature on up to two bodies of water at the same time. For each pool, the PoolWarden includes a pH relay and an ORP relay supplying the input voltage when on, along with 2 auxiliary dry-contact relays that can be used to control a heater and a backup sanitizer (when the primary sanitizer is a salt system). Water measurements are taken continuously while PoolWarden’s internal relay programing determines if chemical adjustments are needed. Energy management is supported by providing two set points per day for heater control. With optional gold ORP probes and TrueDPD Colorimetric sensors, the PoolWarden is ideal for saltwater pools & spas.