Since I have been using RO water and making my water additions I have found that my actual mash pH has been consistently 20 to 25 points lower than what the calculator predicts, so I am wondering if I have my water calculator settings correct or not. What I have been doing is adding my water agents to the full volume of water in the batch, so the mash and sparge water are the same profile. The example below is a Black IPA. Due to the dark malts pH came in at 5.19, which is why I have added the baking soda. Am I doing this right? Should I treat the mash water only, and leave the sparge water as straight RO? I feel like a good scientist when I hit my mash temperature, my volumes are spot on, and my gravity readings are close to if not bang on target. I currently feel like a bad scientist with my water chemistry not getting my expected pH readings.