AUSTRALIAN WATER GUIDE
Check your local water hardness and disinfectant
Enter your suburb, city or postcode to see published hardness data, the disinfectant used by your water utility and which shower-filter features are relevant to your supply.
Figures are sourced from the water utility named in each result. Where a verified number was unavailable, the field is marked as a known gap.
Or pick a city
AUSTRALIAN CITY COMPARISON
Compare water hardness and disinfectants by city
This table summarises the utility data currently available for major Australian cities. Missing figures are left unfilled until a reliable source is available.
| City | Hardness mg/L | Reads as | Disinfectant | Source |
|---|---|---|---|---|
| Sydney | about 57 | Soft | Chlorine with ammonia, forming chloramine | Sydney Water |
| Melbourne | 18 | Very soft | Free chlorine, about 0.76 mg/L residual | South East Water, DWQ 2024-25 |
| Brisbane and Ipswich | about 100 | Moderately hard | Free chlorine, about 2 mg/L | Urban Utilities, DW report 2023-24 |
| Perth | 29 to 228 | Soft to hard, by suburb | Chlorine. Chloramine in the Goldfields, not metro | Water Corporation locality tables |
| Adelaide | about 97 | Moderately hard | Chlorine in the metro, chloramine on long pipelines | SA Water |
| Canberra | about 43 | Soft | Chlorine | Icon Water |
| Hobart | not obtained | Known gap | Not obtained | None. See below |
Hardness is expressed as milligrams per litre of calcium carbonate, written mg/L as CaCO3. Sydney Water classifies anything below 60 mg/L as soft.
HOW SHOWER FILTRATION WORKS
Chlorine, chloramine and vitamin C filtration
Why chloramine matters in Sydney
Free chlorine leaves water readily. That is why a glass left on the bench overnight tastes different by morning, and why the smell is so obvious in a hot shower.
Chloramine behaves differently. It is chlorine bonded with ammonia, and it is deliberately more stable, because the whole point of using it is to hold a disinfectant residual all the way to the far end of a long pipe network. Sydney Water uses it for exactly that reason.
Because chloramine is more stable than free chlorine, Sydney shoppers should check whether a shower-filter medium is suitable for chloramine as well as reviewing water hardness.
How vitamin C reacts with chlorine compounds
Ascorbic acid, which is vitamin C, reacts with both free chlorine and chloramine and chemically reduces them to chloride. It is a reaction, not a trapping.
Activated carbon works the other way round: it holds things on its surface. Carbon handles free chlorine well and has a much harder job with chloramine, because chloramine has to be broken apart rather than simply caught.
This reaction is why vitamin C is used in shower filtration for water supplies that may contain free chlorine or chloramine.
Limits
Where local water data is limited
Water conditions vary within cities and over time, so use these figures as a guide and check your utility for the latest local information.
Hobart
We have no verified hardness figure for Hobart.
Your street is not your city
Utilities blend water from different sources, so hardness can vary by suburb and season. A city figure is a useful guide, while your utility or a tap-water test can provide more local detail.
Suburb data outside Perth
Perth is the only city here with suburb-level numbers, because Water Corporation publishes locality tables and most utilities do not.
CHOOSE A SUHAE SHOWER FILTER
Choose filtration for your local water and shower setup
SUHAE uses vitamin C filtration for chlorine compounds, with formats for compatible handshowers, rainshowers and existing showerheads. If limescale is your main concern, review local hardness first because chlorine filtration does not soften water.
Compare SUHAE shower filters