If your regulator has no built in solenoid, the In-line Solenoid Valve by Archaea will help you control the CO2 flow to your aquarium tank. Automation of daily CO2 dosing is made easy when this solenoid valve is connected to a standard wall timer.
Just a little something to help you fine tune your CO2 experience. No fuss, just set the CO2 regulator to what you need, connect it to this guy and plug it into a timer...and you're all set. Shout to the ALA guys for helping me find the right part in stock.