Thank you for your input, but I am not guessing. And I am not sure how you know that I need to buy more stuff, when I said that I bought a generator and the stuff you need to go with it.

There are two ways to input C02, and have it shut off at the right ppm. (1) have your controller hooked up to a ppm meter, that sends a signal to the controler at the proper ppm. (2) have your controler hooked up to a timer, that sends a signal to the controler at the proper time. You just need to figure out what that time is.

At this point, it costs roughly $500 extra to use method one, so I went with the timer. I talked with the guy at the hydro store about this, and he says that he hardly ever sales a ppm controler. Almost everyone who buys from that store uses a timer to shut off the co2 at the proper point. I don't think the vast majority are doing it wrong. There are many ways to figure this out using time instead of ppm for shut off points. Green Air has a calculator that tells you how long to leave the co2 on for your particular enclosed space. If Green Air recommends controling the co2 with a timer as one method, can it really be that bad?

How many of you guys use a timer?
How many use a ppm controller instead?
Where do I find the cheapest ppm controler, and how much is it, and do I want to buy the cheapest one?

Now would anyone like to take a stab at answering my original question?