Hey guys/gals,
I am using beersmith to do my recipe and water adjustments and whatnot…
When I go to the water adjustment tool (first time), Is the batch volume = total water needed (i.e. 7.64gal) … or… batch volume = batch size (i.e. 5gal)???
I am going to guess = total water needed (mash+sparge)
I know it is probably a stupid question but after hours of water adjustment calculations am blown!
No such thing as a stupid question.
Batch size typically refers to the amount of wort that you end up with in the fermenter. Although if your talking about the water adjustment tool, I think it refers to base water which is different. I actually use Bru’n water. I like it a bit better, even though the beersmith software is awesome, and I use that for everything else. 
I recommend skipping beersmith when it comes to water and using bru’n water instead.
+1
+2, I have paid for both and have never used beer smith’s water treatment section
Since I have Brunwater, I use it exclusively. So I have never tried Beer smith’s water profile. Even so, most of these things contemplate batch size as the finished wort collection and use total water volume as the reference to the gross starting point for water.