Agrowtek GrowControl PHX pH Monitor, Transmitter & Logger KitA Precise Automatic pH Monitor, Transmitter, & Logger Built On A Decade Of Proven Technology AgrowDose PHX monitoring systems are autonomous pH set point systems consisting of a digital PHX hydroponics controller and temperature, pH, and optional ORP or DO probes. Precision sensors and rugged pumps offer reliable and accurate control of reservoirs large and small. Ideal for applications such as aquarium and aquaponics, pool & spa or industrial