How Your Water Conditioner Works - Culligan HE Owner's Manual

How Your
Water
Conditioner
Works
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6
Why Water Gets Hard And How It Is Softened
All of the fresh water in the world originally falls as rain, snow, or sleet. Surface water is drawn upward
by the sun, forming clouds. Then, nearly pure and soft as it starts to fall, it begins to collect impurities as it
passes through smog and dust-laden atmosphere. And as it seeps through soil and rocks it gathers hard-
ness, rust, acid, unpleasant tastes and odors.
Water hardness is caused primarily by limestone dissolved from the earth by rainwater. Because of this,
in earlier times people who wanted soft water collected rainwater from roofs in rain barrels and cisterns
before it picked up hardness from the earth.
Some localities have corrosive water. A softener cannot correct this problem and so its printed warranty
disclaims liability for corrosion of plumbing lines, fixtures or appliances. If you suspect corrosion, your Cul-
ligan Man has equipment to control the problem.
Iron is a common water problem. The chemical/physical nature of iron found in natural water supplies is
exhibited in four general types:
Dissolved Iron—Also called ferrous or "clear water" iron. This type of iron can be removed
1.
from the water by the same ion exchange principle that removes the hardness elements, calcium
and magnesium. Dissolved iron is soluble in water and is detected by taking a sample of the
water to be treated in a clear glass. The water in the glass is initially clear, but on standing
exposed to the air, it may gradually turn cloudy or colored as it oxidizes.
2. Particulate Iron—Also called ferric or colloidal iron. This type of iron is an undissolved par-
ticle of iron. A softener will remove larger particles, but they may not be washed out in regen-
eration effectively and will eventually foul the ion exchange resin. A filtering treatment will be
required to remove this type of iron.
3. Organic Bound Iron—This type of iron is strongly attached to an organic compound in the
water. The ion exchange process alone cannot break this attachment and the softener will not
remove this type of iron.
Bacterial Iron—This type of iron is protected inside a bacteria cell. Like the organic bound
4.
iron, it is not removed by a water softener.
When using a softener to remove both hardness and dissolved iron it is important that it regenerates more
frequently than ordinarily would be calculated for hardness removal alone. Although many factors and
formulas have been used to determine this frequency, it is recommended that the softener be regenerated
when it has reached 50–75% of the calculated hardness alone capacity. This will minimize the potential
for bed fouling. (Iron removal claims have not been verified by the Water Quality Association.)
If you are operating a water softener on clear water iron, regular resin bed cleaning is needed to keep
the bed from coating with iron. Even when operating a softener on water with less than the maximum
of dissolved iron, regular cleanings should be performed. Clean every six months or more often if iron
appears in your conditioned water supply. Use resin bed cleaning compounds carefully following the
directions on the container.
CAUTION! Do not use where the water is microbiologically unsafe or
with water of unknown quality without adequate disinfection
before or after the unit.