I brew 2.5 gallon BIAB batches with a 5 gallon pot. I typically run grain bills in the 4 - 7 lb neighborhood, mash somewhere between 1 - 2 qts/lb, and batch sparge with just my DHW @ 130F to get to my pre-boil volume, usually 3.5 gallons. Last I checked I was getting over 80% using the...