Good morning to all. I'm new to brewing (brewed 4 extract kits to date) and I'm researching all grain brewing. I've read about water calculations and watched youtube videos but I can't wrap my head around determining the amounts of water needed. The most basic calculation I've seen is #lbs of grain x 0.375 (say 9lbs x 0.375=3.375gal ) to determine the mash water volume and multiply that volume by 1.5 (3.375gal x 1.5 = 5gal) to determine the volume of sparge water. If I want a 5 gal post-boil batch size does that mean I need to boil off 3.375gallons? Are the multipliers even correct? All the other calculations I've seen appear to be very complicated.