
http://www.jimsbeerkit.co.uk/water.html gives:
130 ppm for Ca
But:
https://www.brewersfriend.com/water-chemistry/ gives: (with the historic option)
270 ppm for Ca
That seems quite a big difference? Although I've never treated my water before, so could be misunderstanding something.
I do notice the historic decarbonated option gives 180ppm though. I'm not sure what that really means though.
I'm inclined to go with Graham's calculator values, but I'm just wondering what the difference is due to.
I think I'm going to have to buy the Water book soon!
Edit: Just found this:
https://www.brewersfriend.com/brewing-w ... -profiles/
"Burton on Trent is known for water with very high sulfate content. This profile has been constructed from a water analysis of Burton well water published in “Burton-on-Trent, Its History, Its Waters and Its Breweries” from 1869."