Kinetico has their own control valve, it is centuries old water power,
non-electric. Usually they require a prefilter to prevent 'dirt' from
getting into the control valve and stopping it from counting down the
gallons which prevents it from regenerating.

You never want to use a softener that requires the maximum salt dose
for the volume of resin, nor run a softener to exhaustion before
regenerating it.

Hard water wears clothing and all other fabrics out long before they
should have to be replaced. Softening just the hot side is not a good
idea IMO. Mixing any hard water with soft water and you have hard
water. Soften all the water to all fixtures and get the many benefits
of softened water.

Renting a softener isn't a good idea IMO, you're throwing money away.
Search the internet and newsgroups for info on softeners and go from
there. If you buy over the internet you can save from a few hundreds to
a couple thousand dollars and get equal or better quality than a local
dealer. And sttay away from big box store brands unless you want to
replace the softener in 2-6 years. Look for a softener with the Clack
WS-1 or Fleck 7000SE control valve. Search for them inside "". They are
the best for a DIYer that wants to be able to replace a part if needed.
Neither require control specific special Fleck tools like the Fleck
5600, 2510, 9000 and 9100 controls do.

You do not need a plumber to install a softener, unless you live in
Mass. where homeowners are not supposed to do any of their own
plumbing..... Any DIYer can do it if if they have the desire and will
buy some basic tools. It's very simple and takes 1.5-2 hours including
clean up. Anyone can learn to solder in less than 30 minutes of
practice.

Some softeners leave minimal water in the brine tank and add the water
for this regeneration as the first cycle of this regeneration (pre
fill) and others add it as the last cycle of this regeneration (post
fill); they have the most water left in the brine tank.

Anytime you taste salty water, the most frequent cause is something
using water during a regeneration, but there could be inadequate rinse
also or... too much water in the brine tank and slow rinse was
incapable of getting rid of all of it.

The added sodium a softener adds t othe water is 7.875 mg/l, roughly a
quart, per grain per gallon of ion exchange (compensated hardness).
Usually that's less than you get in a glass of skim milk; which is said
to be 530 mg.
http://www.awqinc.com/sodium_softening.html

Gary
Quality Water Associates
http://www.qualitywaterassociates.com