SRJHops
Why did the rabbit like NEIPA's so much?
6 to 9 or so is the general range I'd expect water pH to be. If water pH 6 yields a prediction of 5.30 and 9 yields 5.32, then the 5.31 that you get for no entry is probably guessing something in between.
I think I'll keep entering the ph, but the learning (thanks!) is that the grain and salt additions are really what move the numbers. The calculator must have that 6 -9 range as part of how it works, but numbers outside of that range make it go a bit wonky. Otherwise I don't know how to explain that entering 3 or 4 for the starting water ph makes it predict 8.75 ph including the grain...