Water Softeners Buying Guide: What to Check Before You Buy

Hardness and what a softener removes: Hardness is caused mainly by calcium and magnesium in the water. Total hardness is those two added together and expressed as a calcium carbonate equivalent. Softening is the treatment that removes calcium and magnesium salts, particularly carbonates and bicarbonates.^[1],[2]

Hardness bands: Under 60 mg/L is soft but possibly corrosive. From 60 to 200 mg/L is good quality. From 200 to 500 mg/L brings increasing scaling problems, and above 500 mg/L means severe scaling. The Australian guideline is that total hardness should not exceed 200 mg/L to limit scale in hot water systems. Hardness can be measured in a lab by titration with EDTA, so ask your water utility or a lab for a figure rather than guessing.^[1]

Is it worth it? Total hardness in major Australian supplies runs from about 5 mg/L to about 380 mg/L, so the answer depends heavily on where you live. Hard water can build scale on water heating elements and cause problems with soaps and detergents. If your supply sits well under 200 mg/L, a softener may add little. Check your local figure with your water supplier first.^[1],[2]

Sodium: Domestic water softeners can add to the sodium in drinking water. Major Australian supplies range from 3 to 300 mg/L sodium, with a typical value of 50 mg/L. The aesthetic guideline, based on taste, is 180 mg/L. Softening very hard water can push sodium high enough to taste salty, but the guidelines say this is unlikely to be a health concern.^[2],[3]

Sodium and health: Water makes only a modest contribution to total sodium intake. Average Australian dietary intake is about 4 g a day, and low-sodium diets may restrict it to under 2 g. Adults are advised to aim for no more than 2,000 mg of sodium a day. There is no health-based guideline for sodium in water, but doctors treating people with severe hypertension or congestive heart failure should know if drinking water exceeds 20 mg/L. If that applies to you, talk to your doctor before buying. The guidelines also encourage steps to cut sodium, such as alternative salts in domestic softeners.^[3],[4]

Magnetic devices versus true softeners: Magnetic scale devices are sold on a different idea from removing calcium and magnesium, and the research is not encouraging. In one consumer trial there was no appreciable difference in scale quantity or texture, and the product was deemed ineffective. In another test a chemical scale inhibitor almost completely eliminated scale, while the magnetic device did not prevent it and slightly increased it. A review concluded the scientific evidence behind these products does not exist, and that reputable controlled studies found they did not perform as advertised. Such devices are not used in municipal water treatment plants.^[5]

Some defenders point to lab studies using much stronger magnetic fields for much longer than consumer products provide, so those results do not describe what a shop-bought unit does.^[5]

Pressure, flow and appliance limits: Compare a model's rated flow with your household demand, and its operating pressure range with your supply pressure. One listed household unit shows 40 L per minute and a 138 to 862 kPa operating range, and another is listed at 30 L per minute. If an appliance needs a lower pressure than the supply provides, the plumbing standard requires a pressure limiting or reducing device. Pipework and fittings must also be sized to give the device or appliance an adequate water supply.^[6],[7]

Chlorine, nitrate and pH: The health guideline for total chlorine is 5 mg/L, and major Australian supplies typically carry about 0.2 to 0.5 mg/L of free chlorine. Chlorine can be removed by aeration, sunlight or reducing agents such as sodium bisulfite.^[8]

Nitrate in major Australian supplies ranges up to 51 mg/L, with typical concentrations usually under 0.15 mg/L. The guideline value is 50 mg/L, set to protect bottle-fed infants under 3 months. Conventional water treatment is not effective at removing it, and nitrate reduction facilities are expensive to run and use anion exchange resins. If nitrate is a concern, ask your supplier for your local result before choosing equipment.^[9]

pH should sit between 6.5 and 8.5 to limit corrosion and encrustation of pipes and fittings. Below 6.5 or above 11, water may corrode plumbing. Water that is too soft can also be corrosive, so over-softening is not a goal.^[2],[10]

Who can install it: A softener is connected to the water supply, so backflow protection rules may apply. In Victoria, the Barwon Water guidelines say a plumber licensed in water supply by the Victorian Building Authority may install backflow containment devices, and only a suitably qualified person may commission and test them. Barwon Water's guidelines also say medium-hazard properties must as a minimum install a testable double check valve, and that when a water service is renewed, altered or relocated, a device suited to the property's hazard rating must be installed. Ask your plumber to confirm your property's hazard rating and which device applies.^[11]

Rules differ by state and water utility, so check the current requirements with your state plumbing regulator and your water supplier, and ask your plumber which backflow device suits your property.

1. [1]Hardness (as calcium carbonate) (checked 2026-11-11)
2. [2]8.3.4 Softening - Australian Drinking Water Guidelines - NHMRC (checked 2026-11-11)
3. [3]Sodium (checked 2026-11-11)
4. [4]Salt (checked 2026-11-11)
5. [5]Magnetic water treatment technologies - what is the science? (checked 2026-11-12)
6. [6]Puretec SOL40-E3 Water Softener (checked 2026-11-12)
7. [7]Updated plumbing and drainage standards - Part 1: Water services (checked 2026-11-12)
8. [8]Chlorine (checked 2026-11-11)
9. [9]Nitrate and nitrite (checked 2026-11-11)
10. [10]pH - Australian Drinking Water Guidelines - NHMRC (checked 2026-11-11)
11. [11]OFFICIAL OFFICIAL Backflow Prevention and Containment Policy Guidelines (checked 2026-11-11)

Drafted with AI assistance from the sources listed, then fact-checked and edited by the PouchMe team. PouchMe researches products from published information; we have not tested them ourselves.