Yep, crappy water! A lot of my FBI clubmates use it, though. The Carmel water cannot be used for brewing because it is salt-softened by the City.
Martin, can you elaborate? I believe my Minneapolis city water is also salt softened, but my Ward Labs water report indicates that, while fairly soft, it makes for very good brewing liquor. I usually only have to add some calcium or sulfate to achieve most water profiles.
Minneapolis gets their water from the Mississippi if I understand correctly. That is probably not near as hard as the groundwater that my city uses as its supply. The resulting sodium content in the softened water is directly proportional to the hardness of the raw water. I’m my case, that means that my water comes to my house at up to 250 mg/L sodium!!! That is not suitable for brewing. 100 mg/L would be pushing it.
Thus, I have a RO system now.
250 mg/L – ouch! Yeah, my sodium level is only 13.