Originally Posted by week0019
Would this be true for lagers too as I believe they don't ferment as rapidly as ales?
pretty much. A standard gravity beer (around 1.040) will produce about 60 gallons of co2 for every gallon of beer. How fast? I don't know, All the O2 won't be displaced, some of it will end up in the fermentation, but remember unless you are using O2, just about every beer is under aerated at the start.
Long and short, I'd not worry about it.