How does a home water softener work?

We got one a year, maybe two, ago and I'd like to know how it works.
It consists of: 1) a large-ish canister main unit that has the main
control panel and a couple hundred or so pounds of salt 2) a 5-gal
holding tank and 3) an under-the sink reverse-osmosis filter system with
faucet installed in sink. With plastic tubing connecting the units
obviously.
We had a repair/maintenance guy here a week or two ago and we asked him
the same thing, concerned that a couple of us have blood pressure issues
and didn't want additional sodium in the water.
Here's what I think he said (which may or may not be what he actually
said): it softens the water for the whole house, but the salt was only
to clean out the holding tank. About once a day, the holding tank is
emptied and salt water fills the tank. It is then emptied and fresh
water flushes the tank and is then emptied. The R-O unit then starts to
fill the tank again.
There is no brand on the unit, but the commands are in english and
french.
How does a home water softening system work in general? How does it
'soften' water? What physical/chemical/mechanical principles does it
work on? Does it really only use the salt for washing out the holding
tank?

Thank you for the help!

"Pringles CheezUms" wrote...

How does a home water softener work?

We got one a year, maybe two, ago and I'd like to know how it works.
It consists of: 1) a large-ish canister main unit that has the main
control panel and a couple hundred or so pounds of salt 2) a 5-gal
holding tank and 3) an under-the sink reverse-osmosis filter system with
faucet installed in sink. With plastic tubing connecting the units
obviously.
We had a repair/maintenance guy here a week or two ago and we asked him
the same thing, concerned that a couple of us have blood pressure issues
and didn't want additional sodium in the water.
Here's what I think he said (which may or may not be what he actually
said): it softens the water for the whole house, but the salt was only
to clean out the holding tank. About once a day, the holding tank is
emptied and salt water fills the tank. It is then emptied and fresh
water flushes the tank and is then emptied. The R-O unit then starts to
fill the tank again.
There is no brand on the unit, but the commands are in english and
french.
How does a home water softening system work in general? How does it
'soften' water? What physical/chemical/mechanical principles does it
work on? Does it really only use the salt for washing out the holding
tank?

Thank you for the help!

http://en.wikipedia.org/wiki/Water_softener

Sat, 05 Apr 2008 21:22:28 GMT from Craig :
http://en.wikipedia.org/wiki/Water_softener

So it would seem that home water softeners work by taking out
calcium, magnesium, manganese, and iron ions and replacing them with
sodium ions.

I wonder about the concentration. Is the OP right to be concerned
about sodium intake from softened water?

--
Stan Brown, Oak Road Systems, Tompkins County, New York, USA
http://OakRoadSystems.com
Shikata ga nai...

"Stan Brown" wrote...

Sat, 05 Apr 2008 21:22:28 GMT from Craig :
http://en.wikipedia.org/wiki/Water_softener

So it would seem that home water softeners work by taking out
calcium, magnesium, manganese, and iron ions and replacing them with
sodium ions.

I wonder about the concentration. Is the OP right to be concerned
about sodium intake from softened water?

Yes, softeners that recharge the ion exchange resin by using salt are a
concern. Back as a kid, my family had a water softener--but unsoftened cold
water was piped to our kitchen sink (and outdoor spigots) for drinking and
cooking rather than softened water.

Craig

In article 6E4Kj.74729$D_3.9456@bgtnsc05-
news.ops.worldnet.att.net, says...

"Stan Brown" wrote...

Sat, 05 Apr 2008 21:22:28 GMT from Craig :
http://en.wikipedia.org/wiki/Water_softener

So it would seem that home water softeners work by taking out
calcium, magnesium, manganese, and iron ions and replacing them with
sodium ions.

I wonder about the concentration. Is the OP right to be concerned
about sodium intake from softened water?

Yes, softeners that recharge the ion exchange resin by using salt are a
concern. Back as a kid, my family had a water softener--but unsoftened cold
water was piped to our kitchen sink (and outdoor spigots) for drinking and
cooking rather than softened water.

I assume it wasn't piped to the outdoor spigots for cooking or
drinking, rather because it was a waste to water the lawn or wash
the car with "softened" water.

--
Keith

In article , krw wrote:

I assume it wasn't piped to the outdoor spigots for cooking or
drinking, rather because it was a waste to water the lawn

Main reason is that it's harmful to plants.

or wash the car with "softened" water.

Soft water is desirable for washing cars -- it doesn't leave nearly as many
spots on the finish as hard water does.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

The stat that I heard was if you drank an average amount of water, the extra
sodium was equivalent to the sodium you would get in a slice of bread. IF
sodium is a concern, you could always recharge with Potassium Chloride
instead of salt (available most everywhere water softner salt is sold). I
think the potassium might cut down on the efficiency abit and may require
more frequent recharges

"Craig" wrote in message
...

"Stan Brown" wrote...

Sat, 05 Apr 2008 21:22:28 GMT from Craig :
http://en.wikipedia.org/wiki/Water_softener

So it would seem that home water softeners work by taking out
calcium, magnesium, manganese, and iron ions and replacing them with
sodium ions.

I wonder about the concentration. Is the OP right to be concerned
about sodium intake from softened water?

Yes, softeners that recharge the ion exchange resin by using salt are a
concern. Back as a kid, my family had a water softener--but unsoftened
cold water was piped to our kitchen sink (and outdoor spigots) for
drinking and cooking rather than softened water.

Craig

"jmagerl" wrote...

The stat that I heard was if you drank an average amount of water, the
extra sodium was equivalent to the sodium you would get in a slice of
bread.

See: http://www.inspect-ny.com/septic/watersoft.htm

In part, it says:

HEALTH RISKS - of Water Softeners - Water Softener Salt in Drinking Water
and Other Risks
SALT IN DRINKING WATER: A properly-adjusted water softener puts about 8 mg
of salt (sodium, or NaCl) in each liter of treated water for each grain of
hardness removed. Water at 10 grains of hardness will have 80 mg of salt/L.

A water softener which is improperly adjusted or malfunctioning may place
higher levels of salt into the building water supply. The salt level in the
backwash discharge from a water softener can contain high levels of salt but
that discharge is not delivered to the building water supply but rather to a
drain.

In my water quality articles I suggested that people who need to avoid salt
even at low levels may want to install a bypass water line to deliver water
to one sink tap for drinking and cooking, or they can install a reverse
osmosis system to remove salt from water (and other contaminants) at the
point of use, typically in the kitchen.

In article , Pringles CheezUms wrote:
How does a home water softener work?

Damn, Google must be broken again.

On Apr 5, 4:41 pm, Pringles CheezUms wrote:
How does a home watersoftenerwork?

We got one a year, maybe two, ago and I'd like to know how it works.

How does a home water softening system work in general? How does it
'soften' water? What physical/chemical/mechanical principles does it
work on? Does it really only use the salt for washing out the holding
tank?

Thank you for the help!
For a visual of softening 101 goto;
www.kenmorewater.com and view the animations.

There is no "salt" added by ion exchange softening but there is 7.85
mg/l of added sodium per gpg (17.1 mg/l or ppm) of exchange IF you use
softener salt to regenerate with. IF you use potassium chloride, then
no sodium is added but potassium is. And before you think that's a
great thing... you can get too much potassium and people with heart
problems should be very careful with potassium intake.

IF you use potassium chloride, and your softener is set for high salt
efficiency, then you will have to increase the salt dose by up to 30%
because potassium is not near as efficient as sodium because all
softening resins are made in the sodium form. There are no potassium
form resins.

For a comparison of sodium in food to softened water see;
http://www.awqinc.com/sodium_softening.html

For more on the added sodium and how a water softener works see;
http://www.wqa.org/sitelogic.cfm?id=1085

Gary Slusser
Quality Water Associates