can you take pics or provide a link to the equipment you bought? I'll be able to help you out a lot more if I can see what you are working with.
Co2 is carbon dioxide, which is what plants breathe. Plants can handle like 5 times the amount that is in the atmosphere today. To give you an idea of what it does, Imagine Lance Armstrong riding a bike with an oxygen bottle providing pure oxygen while riding. It would give him better performance. Same thing with co2 and plants. :thumbsup:
You will want to suck the air through the hood rather thn blow it through. The reasoning is that if you suck it out using the intake of a blower, you have a lower air pressure than outside the system. If there are any leaks, it will just cool the heated air from the hood. If you blow the air through the hood and have a leak, it will heat up your cabinet. Heat is an enemy espescially in close quarters like a small cab.
You will attach a hose to the part of the blower that sucks the air in. Run that hose to one of the things (tube adapter) on the hood. Put a hose on the other "thing" on the hood and run that to outside or wherever you get your fresh air. After that attach a hose to the blowing part of the blower and exhaust it outside or wherever you want that hot air to go. Keep askin questions, thats what we are here for, for you to learn from our mistakes/experiments.