A hydroponic environmental control system that automates the management of the air, temperature, CO2, lighting, and humidity for the optimum growth of plants in a hydroponic growing environment according to user-specified parameters with full logging and reporting capabilities is presented. The device is comprised of digital circuitry that reads sensor information and turn fans on/off, open/close CO2 valves, starts/stops dehumidification, and turns lights on/off. Due to the electrical and humid environment in which the device will be operating, the device is comprised of two modules, each of which is designed for a different environmental setting: (a) the control module, the module with which the user interfaces, is normally located in or near to the hydroponic environment and is thus designed to resist humidity； and (b) the power module, normally located in a dry area, supplies power to both itself and the control module, and contains all of the line-voltage interfaces.
