Well I know you are not going to like my input here but I think you have some more stuff to buy. Namely a CO2 analizer of some sort. You NEED this if you are going to augment CO2 effectively. Ambient CO2 levels in some areas are nearly 1500ppm and there seems to be virtually no need for a CO2 generation system.

You can go cheap and get the CO2 analizer tubes kit for $20. I reccomend a telair or similar digital CO2 meter. If you tamper with the environment like this you need to know what you are doing and what the result is. A guess of a baseline and a guess of addition rate along with a guess of the final result is not a precise way to control a very fragile band of CO2 that is necessary for optimal plant production.

Adding CO2 without analisis would be like adding nutes without a PPM/EC meter.. and in my opinion just as harmful as it can be beneficial..