Typically growers will just plug the regulator into either a timer, or co2 ppm meter. Kind of just depends on how precise you want to be and/or budget. How wide open the regulator should be set depends on the size (cubic feet) of the room, and number and size of the plants. To be honest I don't know anyone who grows in such a small area and uses co2 enrichment.
A typical lamp timer will turn on and off the regulator at preset intervals. Most lamp timers are either 15 or 30 minute minimum settings. Digital timers can give you more control on the on and off duration's, but be careful, they may not have many total settings. So if your going to run short on cycles and frequently during the day, you may be better off with a cycle timer. Cycle timers you set the duration of the on time and the off time and it cycles indefinably on that cycle. Many cycle timers also have a photo cell so it can be set to not go on at all during dark periods.
CT-1 Short Cycle Timer
Autopilot Analog 24HR Recycling Timer
But a co2 ppm meter will be able to turn on and off the regulator to based on preset co2 ppm values. Some can also be set and controlled by temp, humidify, and/or photosynthesis period. It's important to remember that plant co2 intake is affected by temperature and humidity levels, as well as light intensity (par/lxu) during photosynthesis. Here are a couple of videos on setting up the regulator, one using a lamp tier and the others by ppm meters.
CO2 ENRICHMENT USING REG & TIMER
co2 PPM Controller
Here's just one place that sells a variety of co2 enrichment equipment,
Here's some information on co2 enrichment methods as well as understanding indoor climate control and how all the variables affect co2 intake.
Carbon Dioxide Enrichment Methods
Control Yourself: Understanding the Basics of Indoor Climate Control
In such a small space (cubic feet), it will be easy to over saturate with co2. co2 levels above 1,500 ppm. 2,000 ppm start to become toxic to the plants. So you will likely need to use the co2 PPM meters to regulate the co2 levels so you don't over saturate it.