Originally Posted by Drunk Monkey
I am thinking that it will be too heavy and break your stir plate.
That's certainly a possibility...depending on which stir plate you have. Mine have a plastic case and may not stand up to 50 lbs of wort. Also, bottom of the fermenter may be too thick to allow good magnetic attraction between the stir bar and stir plate.
I doubt that you'd really aerate the batch that much even if you could drive a 3" stir bar. You need to generate a lot of turbulence to aerate in the presence of so much CO2. I doubt any of our stir plates would be capable of that sort of thing.
I also doubt that it's necessary in the first place. Let us know what happens if you decide to try it, though.