Looking for common sense solution. This is a community well based water supply. Thinking of doing whole spouse carbon filter and UV for added safety (not espresso quality).

I don't see anything in those numbers that would require a whole house carbon/UV system but nothing wrong with that if you just want to be cautious.

Those numbers tell you nothing reliable about limescale risk or chloride corrosion risk. The chlorine, pH, TDS, and alkalinity numbers look consistent with a very soft well water that has been treated with some sort of chlorination for disinfectant and soda ash for pH adjustment. (Soda ash treatment systems inject small amounts of sodium carbonate, and raise the pH, sodium, alkalinity, and TDS, but not the hardness of the water.) If so, I think all you'd need for espresso equipment would be any good particulates and charcoal or carbon block for chlorine, off tastes and odor. A whole house carbon filter would certainly take care of that.

A simple GH and KH drop titration test kit could be used to verify whether or not this water might be scale prone. You can find them online or buy them from a pet store that sells aquarium equipment.

Thanks for that insight!

I would absolutely agree that I don't see any need for a whole home filtration system in your current case. Hard to say how likely you are to get scale though.

I would recommend, if you really want to be sure, a well maintained localized RO system with a re-mineralization stage or using 3rd wave water packets on non-re-mineralized packages. I've been doing former for years and I've not had any evidence at all of scale.

I ordered the GH/KH test kit to take that variable off the table as well.

Update to include hardness values

Carbonate hardness = 4 grains (55-70 PPM)
General hardness = less than 1 grain (under 17PPM)

Wacobipe wrote:Carbonate hardness = 4 grains (55-70 PPM)
General hardness = less than 1 grain (under 17PPM)

Thanks for reporting back -- good to know. Moderate alkalinity with very low hardness is what you would expect with very soft well water after soda ash treatment. Any softening treatment of the water from the tap would be unnecessary and ineffective.

P.S.
I know the KH kit may call it 'carbonate hardness' but that term has a couple inconsistent definitions. Most water chemists would say that when the hardness is less than your total (carbonate and bicarbonate) alkalinity, your true carbonate hardness is equal to the GH and not the KH. For most natural water the hardness is greater than the alkalinity, so that's why people so often simply refer to the KH as carbonate hardness.

From Hach: