Bluelab CONTPH pH Controller with Hands Free Monitoring and Dosing of Solution Doses pH up or down - use with undiluted Bluelab pH up or down solutions Easy to navigate menu to program and adjust settings Automatic control and monitoring of system pH with reservoirs up to 200 us gallons / 760 l Replaceable peristaltic pump, pH and temperature probes Flashing high and low alarms Please refer the below user manual for reference