For the safe use of CO2 in any aquarium it is higly recommended to automate the system. A control valve will do this for you by connecting to either a simple time switch or a pH controller. The Red Sea solenoid control valve includes both a hose barb with lock nut for in-line connection on the CO2 tubing and a standard 1/8 in. thread for direct connection to a pressure regulator. It runs using very little power and therefore has a low working temperature.