That's exactly what I did! I bought the 20 gal. with the false bottom to use it for both the mash tun and the boil kettle. Now that it's arrived I started to wonder whether I shouldn't have bought the false bottom, since this size mash tun might cause a too-shallow grain bed for my most commonly used batch sizes. Like I said, I want to mainly brew 12-13 gallon batches. I guess I could return the false bottom, and just use the pot for my BK. Then maybe get the 15 gal. for use as my MT. Just hate to have to spend all that $ right away. Maybe I should just get a Spike 20 gal. for HLT, and keep the Blichmann. Do you think it would make a big difference? Oh, and thanks very much for replying to my initial query.