Water softenerS

The ion exchange water softener is the most common tool used in the removal of scale-forming calcium and magnesium ions (known as temporary hardness) from hard water. In many cases, a water softener can also be used to remove ferrous (soluble) iron from a supply. A typical water softener has four major components.

Typical components of a water softener:

a pressure vessel to contain the ion exchange resin

the ion exchange resin

a control valve (i.e. Siata, Fleck or Autotrol)

a brine bin

The size of water softener required varies according to the flow-rate and the hardness of the water.

How does a water softener work?

A standard water softener works by allowing hard water to filter downwards through a bed of ion exchange resin. The ion exchange resin attracts the calcium and magnesium ions (hardness) and replaces them with sodium ions which are less problematic for water systems and will not cause scale build-up. Once the ion exchange resins are saturated with hardness, the regeneration sequence on the water softener begins.

The water softener’s regeneration sequence begins with the backwash cycle. The backwash cycle reverses the flow of the water to pass upwards through the ion exchange resin bed. This operation frees the beads of the ion exchange resin ready for the next step in the regeneration sequence.

Step 2
in a water softener’s regeneration sequence is to saturate the ion exchange resin with a brine solution. It is during step 2 that the ion exchange resin releases the calcium and magnesium ions and replaces them with sodium ions. Both the calcium and magnesium ions flow along with the water and excess brine solution to drain.

Step 3
in a water softener’s regeneration cycle is a down-flow flush to drain. This removes any excess brine left on the ion exchange resin beds.

Step 4
returns the water softener back into service mode.
The frequency of a water softener’s regeneration cycle is usually pre-set, using a timer or a counter-signal from a water meter.

Could switching to softened water help with eczema?

More than 60% of households are located in hard water areas in England and Wales. Research carried out at the University of Nottingham by dermatologists, medical geographers and statisticians in 1998 indicated that hard water could play a part in causing eczema flare-ups in some children.

The study, involving more than 7,500 school age children, found that eczema is around 50% more common in primary schoolchildren living in hard water areas than those who live in soft water areas. This could not be attributed to differences in age or social class.