How Water Softening Works
Calcified water pipe
Hard water scale has
decreased the carrying
capacity of this pipe by
more than 75% of its
original capacity

Normal Operation with Hard Water:

One of the major problems of hard water is scale buildup. This is caused when heat is introduced to hard water, causing the soluble bicarbonates to begin to break down into their insoluble form.

One effect of hard water is that soaps and detergents lose some effectiveness. Instead of dissolving completely, soap combines with the minerals to form a coagulated soap curd. Because less soap is dissolved, more is required. And the sticky insoluble curd hangs around-it clings to the skin and may actually inhibit cleansing. Washed hair seems dull
and lifeless.

In the laundry, things aren’t much better. The soap curd can work its way into your clothes as they’re being washed in your automatic washing machine. This can keep dirt trapped in the fibers, and it can stiffen and roughen the fabric. In addition to affecting the actual washing process, insoluble soap deposits leave spots on everything you wash-from your dishes to the family car-and a soap film will build up in your bath and shower.

Another reason to be concerned about hard water is its effect on your plumbing system. Calcium and magnesium deposits can build up in pipes, reducing flow to taps and appliances. In water heaters, these minerals generate a scale buildup that reduces the efficiency and life of the heater. These deposits cause pressure and flow problems which increases energy use and shortens the life span for your hot water heater and your pipes.

Another big problem with hard water is the iron it may contain. This iron, when exposed to air, oxidizes and forms rust on your porcelain. The natural tendency is to use an abrasive to remove it, which scratches the porcelain, and gives the rust a rough surface in which to entrench itself, making the stain permanent.

Operation with a Water Softener:

In simple terms, it collects the hardness salts [Calcium and Magnesium] within its conditioning tank and from time to time flushes this hardness away to drain during a process called the “regeneration cycle.” During this process salt is automatically taken from a storage area within the softener, which is used to produce a brine cleaning solution. Salt does not soften the water as such, and even from a properly set up softener, there may be a slight taste of salty water.

However, during the regeneration process sodium ions from the brine replace the calcium and magnesium ions that have been collected from the hard water and as a consequence, softened water has a higher sodium content. This is normally not a problem as the added sodium content in a quart of soft water is about the same as a slice of bread.The water softener is the primary equipment used to remove hardness. It works on the principal of ion exchange using ordinary salt or liquid brine as a regenerant.

A resin tank containing a bead-type resin serves as the exchange site. As hard water flows into the tank, the calcium and magnesium ion are exchanged with inert sodium ions. The softening resin is periodically regenerated with a fresh supply of sodium ions while the hardness ions are flushed down the drain during the back washing cycle.

Most popular water softeners have an automatic regenerating system. Today, most water softeners recharge based on how much water is used. When enough water has passed through the mineral tank to have depleted the beads of sodium, the computer triggers regeneration. These softeners often have reserve resin capacity, so that some soft water will be available during recharging.


In ion exchange,
hard water ions
replace sodium
ions on beads.

Process is reversed
to flush minerals away.

How It Works:

Step 1: Backwash. The backwash phase removes dirt from the mineral tank.

Step 2: Recharge. Recharging the mineral tank with sodium from the brine solution displaces calcium and magnesium, which is then washed down the drain.

Step 3: Rinse. The final phase rinses the mineral tank with fresh water and loads the brine tank so it’s ready for the next cycle.