Ok, CO2 enrichment is my game. It makes a big difference, but only if everything else is dialed in perfectly.
In a tent people often ventilate to control heat. In this case you would exhaust out any CO2 that is added.
To use CO2 properly you need a "sealed" grow environment. Thus air conditioning is critical, as is dehumidification.
The way to accomplish this easily with a tent is use the room the tent is located in as a lung room. You can pull air from that room into the tent and exhaust it right back into the lung room 24/7. The lung room temperature is controlled by the AC unit and set to the number required to keep the tent canopy temps inline. A dehumidifier in the lung room controls the humidity in the same manner.
For the CO2 you get a CO2 controller. A good one will read the PPM in the air and add as required to reach your set point.
Using CO2 tanks is one way to get your CO2. When using tanks you want a controller that uses fuzzy logic and sealing the room is key or you will be refilling the tanks more often. A regulator goes on the tank and is plugged into the controller.
A Co2 generator will run on natural gas or propane. This is a better fit for larger grows but not for a tent grow.
Exhale bags are worthless as tits on a nun so save your money there, especially if you will exhaust the CO2 faster than it's produced.
If you need to know more just ask away, but it's not a cheap endeavor and probably not worth all the extra bullshit for a small grow.