I put this recipe in beersmith and it says to mash with like 12.something quarts of water and sparge with 19.something. Does this sound right?
the amount of water needed depends solely on how you are mashing , if you sparge, and your equipment. For me, I do my 5 gallon batches BIAB and 10 gallon batches I do traditional 3V with batch sparge.
If you setup your equipment correctly in beersmith2, then it should be close on the water needed. the calculator listed above is also a great tool to have and will get you the answer you want. just a matter of personal preference