The PC PPM-B1, digital Co2 controller, provides simple and precise control of a 240-volt co2-generating device with modes for both increasing and decreasing co2. Also featuring Fuzzy logic operation which offers additional accuracy when utilizing compressed gas for co2 supplementation. Adjustable set points range from 400-2000 parts per million with an accuracy of +/-100 PPM and an adjustable deadband. A remote sensor, with 4.5m cable, accurately monitors the gardens PPm levels and relays this information to the controller for display in real-time. An integrated photocell allows for day, night, or continuous operation and the unit records maximum and minimum values for later viewing.