Clean water in
Water Softeners
Hardness out. Scale, white spots and failing geysers with it.
Hard water is water carrying dissolved calcium and magnesium. Heat it and they come out of solution as scale — on taps, tiles, shower heads, inside geysers, heat pumps and boilers. A softener takes those minerals out before they ever reach a tap.
What it means
“Hardness” is the amount of calcium and magnesium dissolved in water, usually reported as mg/l (ppm) of calcium carbonate. Borewell water often runs into the hundreds.
Hardness is not dirt — the water can look perfectly clear. The damage shows up later: white spots on glass and tiles, stiff laundry, soap that will not lather, and scale that insulates heating elements so they work harder and fail sooner.
A softener does one job — it removes hardness. It does not lower total dissolved solids, remove bacteria or improve taste. That is why it is usually one stage in a treatment train rather than the whole answer.
How it works
Step by step, as drawn in the diagram above.
- 1
Hard water enters the valve
The control valve on top of the resin vessel sends incoming water down through the resin bed.
- 2
The resin swaps ions
Resin beads hold sodium. As water passes, calcium and magnesium cling to the beads and sodium is released in their place.
- 3
Soft water leaves
Water collected at the bottom of the bed rises through the centre tube and out of the valve, softened.
- 4
The brine tank waits
Beside the vessel a brine tank holds salt dissolved in water, ready for the next regeneration.
The regeneration cycle
When the resin is full of hardness, the valve regenerates it — automatically, usually at night.
- 1 Service Normal softening, water flowing down through the bed.
- 2 Backwash Flow reverses upward to lift and loosen the bed and wash out trapped sediment.
- 3 Brine draw Salt brine is drawn through the resin; the strong sodium solution pushes the calcium and magnesium off.
- 4 Slow rinse Water follows the brine slowly, carrying the released hardness to drain.
- 5 Fast rinse A quick rinse resettles the bed and flushes the last of the brine.
- 6 Brine refill The brine tank is refilled so salt dissolves for next time.
What it takes out
- Calcium and magnesium (hardness)
- Small amounts of dissolved iron, in some resins
- The scale that forms when hard water is heated
What it does not
- Total dissolved solids stay much the same
- Bacteria and viruses
- Chlorine, taste and odour
- Suspended silt — filter it first
Where it is used
- Homes and villas
- Apartment blocks
- Hotels and hospitals
- Laundries
- Boiler and cooling-tower feed
- Ahead of heat pumps and geysers
What we size it on
- Hardness of the raw water, from the water report
- Daily water use, and the peak flow the building draws
- How often it may regenerate — daily, or every few days
- Space for the vessel and the brine tank, and a drain nearby
Looking after it
- Keep the brine tank topped up with softener salt
- Check the soft water’s hardness now and then
- Clean the brine tank and valve injector periodically
- Resin lasts years, but chlorine and iron shorten its life — pre-filter where needed
Questions, answered
Does softened water taste salty? ＋
Not noticeably at typical hardness levels. The sodium added is in proportion to the hardness removed; for very hard water, or anyone on a low-sodium diet, drinking water can come from a separate RO tap.
Will a softener reduce TDS? ＋
No. It swaps calcium and magnesium for sodium, so total dissolved solids stay much the same. High TDS calls for reverse osmosis.
How often does it need salt? ＋
That depends on the hardness and how much water you use. The softener calculator estimates salt per regeneration and how often it regenerates.
The rest of the treatment train
Clean water in
Sand & Carbon Filters
Particles out with sand. Chlorine, odour and colour out with carbon.
Clean water in
Ultrafiltration (UF)
Particles and microbes out. Minerals stay in.
Clean water in
Industrial RO Skid Systems
Dissolved salts out — the one thing no filter can touch.
Clean water out
Sewage Treatment Plants (STP)
A building’s sewage, treated well enough to use again.
Clean water out
Effluent Treatment Plants (ETP)
Industrial effluent, treated to meet discharge or reuse norms.
Send us your water report
Or tell us where your water comes from — we design the treatment train, install it and stand behind it.