Water softeners in Australia: how they work and when they are worth it
A softener fixes scale, not taste or safety. Whether you need one depends on how hard your water is and what the scale is costing you.
A water softener removes the calcium and magnesium that make water hard, and swaps them for sodium or potassium. It cures scale. It does nothing for taste, chlorine or safety. Most Australian households do not need one, but some do.
Whether you are in the second group depends on one number: how hard your water actually is.
How a water softener works
Most home units use ion exchange. Water passes through a tank of resin beads that hold sodium. The beads trade it for the hardness minerals as the water flows past. When the beads are full, the unit flushes itself with a salt solution and starts again.
That flush uses water and salt, and the waste has to go somewhere. Some councils and water authorities have rules about where it can be discharged.
Check your hardness first
Hardness varies a lot between suburbs, towns and states. Your water utility publishes figures for its supply, and a test kit gives a rough check at home. Our guide to the water hardness test shows how to read the result.
If your water is only mildly hard, a softener is hard to justify. Cleaning scale off a kettle now and then costs far less than buying, running and servicing a unit.
When a softener makes sense
It earns its place where the water is very hard and the scale is doing real damage. Think of a hot water system that keeps losing efficiency, tapware that clogs up, or a dishwasher that coats itself in white crust.
- Very hard supply, confirmed by your utility or a test.
- Scale building up on hot water equipment or fittings.
- Appliance makers that void cover when hard water is used.
If none of those apply, you can usually skip it. Read more on what hard water does before you spend anything.
What to ask before you buy
Ask how much salt and water it uses each cycle. Ask where the waste goes. Ask whether it can be installed on the whole house or only on the hot side. You may not want softened water at every tap, especially the one you drink from.
Be wary of anyone who sells one without knowing your hardness figure. And a softener is not a filter: it will not remove chlorine, bore water minerals such as iron, or germs. For those, see whole house filters.
Softener, filter or doing nothing: how to choose
| Your situation | Likely best option | Why |
|---|---|---|
| Mildly hard water, an occasional scale on the kettle | Do nothing | Descaling costs far less than buying and running a unit |
| Very hard water, scale on hot water equipment | Talk to a licensed plumber about a softener | Scale is doing real damage |
| Chlorine taste or smell | A filter, not a softener | A softener will not remove chlorine |
| Iron staining from bore water | A treatment matched to a lab result | A softener is not a filter |
| Appliance maker limits water quality | Check the warranty first | Some makers void cover with hard water |
| Worried about germs | A laboratory test | Softeners do not remove germs |
Whatever you choose, confirm your hardness figure first. Our guide to the water hardness test shows how.
Running costs and chores that come with a softener
The price of the unit is only the start. Ask about these before you agree to anything.
- Salt. The unit flushes with a salt solution, so you will need to top it up.
- Water. Each flush uses water. Ask how much per cycle.
- Waste. The flush water has to go somewhere. Some councils and water authorities have rules about where it can be discharged.
- Servicing. Ask who services it and how often.
- Where it fits. Whole house or hot side only. You may not want softened water at the drinking tap.
- Licensing. Connecting one to your water supply is licensed plumbing work.
If none of these appeal, what hard water does to your home explains simpler ways to live with scale.
Frequently asked questions
Do I need a water softener in Australia?
Most homes do not. It is worth considering only where your water is very hard and the scale is damaging equipment.
Does a water softener make water safe to drink?
No. It only reduces hardness minerals. It does not remove germs, chlorine or contaminants.
Can I install a water softener myself?
Connecting one to your water supply is licensed plumbing work. Check the rules with your state or territory regulator.
What is the difference between a softener and a filter?
A softener swaps hardness minerals for another mineral. A filter removes particles or chemicals. They solve different problems.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- NHMRC. Australian Drinking Water Guidelines
- Sydney Water. Water supply, wastewater and stormwater services