here in Jackson, Missippi our water hardness is <1 gpg: 17 ppm. I'm dealing with a commercial espresso machine (la Pavoni BarT2VNUL) which came with an 8 liter softener. The manual recommends 1.5Kg (3.3lbs) of rock salt per regeneration; i guess that's for the water hardness of France. Do I even need to use the softener? If so, I'm thinking that less sodium, about <1lb of salt, should be sufficient; got any feedback?