I use a Blichmann BrewEasy system with the BIAB mash profile as suggested. When I calculate acid to add (I start with RO water) i would guess its calculating for the entire volume of water. When I mash in however only a portion of the water is used and sits in the mash tun for 10-15 minutes before I start recirculation. Given the water:grain is not truly full volume for the first 10-15min will this affect the amount of acid to use and should I calculate the acid based on the amount of water I intend to put in the top mash tun rather than the entire volume?