You're paying way more than just the cost of "a couple extra bucks...
for detergents"! A 1/16" of scale on an electric water heater element
can cost you up to 27% of every dollar you spend to heat water. In gas
and oil fired heaters, it's up to 33% of every dollar. AND, there are
many other hidden costs you aren't aware of, like everything you
launder in hard water wears out faster, water using appliances and
plumbing valves fail quicker etc..
If you'll check the label on your loaf of white bread, you should see
about 120-150 mg of sodium per slice. A glass of skim milk is said to
have 530 mg of sodium. The sodium added by a water softener is 7.85
mg/l, roughly a quart, per grain per gallon of exchange. I.E. 12 gpg
hard water = 7.85*12 is 94.2 mg of added sodium per roughly a quart. So
eat a sandwich less or drink less skim milk or give up a pretzel or
potato chip and get on with life
And not softening all the water in the house may be okay, although IMO
it's a dumb idea, but if there's iron and/or manganese in the water,
who wants rust stains in their toilets and kitchen sink? The vast
majority of softeners soften all the water to all fixtures in the
house/building. That's the right way of doing it because then you get
the benefits of softened water everywhere.
Water is either soft(ened) or hard. It can not be "too soft"; it's
either got one or more gpg of hardness in it or 0 gpg of hardness in
it; speaking strictly of residential waters, commercial/industrial
waters in many cases require less then 17.1 ppm/mg/l (1 gpg).
Some people, although very few, add some hard water back into the
softened water rather than get used to their skin's natural oils making
them feel slippery while they shower in softened water.
The use of potassium or sodium chloride makes no difference in the
softness of the water UNLESS the softener is leaking hardness because
of the use of potassium chloride. In many cases you need a higher salt
dose than sodium chloride requires; from 12% to 30% for high efficiency
Quality Water Associates