Doug,

How hard the mixture will be obviously is dependent on how hard the water
is
to begin with -- but the idea that mixing hard and soft water produces
water
just as hard as it was to begin with is absolute nonsense.

Yeah, I said less hard but still hard in my post. Not sure what you
thought I meant.

Whether you
perceive a benefit or not is subjective, but there *is* a difference.
Water
hardness is measured in grains per gallon; regardless of what hardness
level
'x' you might have in your water, if you mix a gallon of it with a gallon
of
water of hardness zero, you *obviously* have a hardless level of one-half
'x'.


My water is hard, about 35 gpg. So using your plan of softening only the
water heater will accomplish what? Let's run the shower. Mostly hot water,
sure but I do like to run a bit of cold. So what's the hardness of the water
running through the cold pipes and faucet (35 gpg), and what's the hardness
of the water running through the shower head (I'm guessing 3 gpg)? Still
pretty hard so the cold pipes, cold faucet and shower head will all begin to
clog due to deposits. And the soap won't suds. So what advantage is gained
by only softening the hot water?
Every sink in my house has an aerator screen. With your plan I'd be
replacing them often. The washing machine cold water valve would clog and
the soap would not suds. Your plan would fail to do anything for more than
half the plumbing and fixtures in a house.
The plan is to reduce the hardness of the water to the point where the
soap suds well, and there are't clogging deposits.

Dave M.