From Joel: "Cubic feet have nothing to do with grams or ounces of 'baking soda'."
Sorry I didnt make it clear. The CO2 calculator in that link gives the amount of CO2 required in cubic feet. That's what I was wondering, how much baking soda would you need to react with vinegar to get required cubic feet of CO2?

From Newgroweroldsmoker: "when the sugar exhausts add some more..."
This seems like a very usable process. How do you tell that the sugar has exhausted? and will the water evaporate? if so, then you would just keep adding water to maintain the same volume?