On headline numbers, Adelaide has the tougher water: harder (about 100 vs 77 mg/L metro), and dramatically higher in dissolved solids (about 480 vs 391 mg/L TDS), which is why taste complaints are an Adelaide institution. The caveat: Perth’s supply-zone averages span roughly 29–228 mg/L, so a Perth home in a hard northern zone can out-scale the Adelaide average.
Side-by-side data
All figures are from each utility’s own published water quality reporting — the same dataset behind our 8-capital water quality lookup.
| Measure | Perth | Adelaide |
|---|---|---|
| Hardness (metro) | 77 mg/L (zones 29–228) | ~100 mg/L (zones 70–115) |
| Total dissolved solids | ~286–400 mg/L | ~480 mg/L metro (280–510) |
| pH | ~7.8 | ~8.0 |
| Disinfectant | Chlorine (chloramine some areas) | Chloramine |
| Fluoride | Added | ~0.56 mg/L |
| Source | Water Corporation, 2023–24 | SA Water, 2023–24 |
What Perth homes deal with
Perth’s blended desal-groundwater-dam supply makes it the most variable capital in the country. Metro zones commonly sit in the 60–80 mg/L moderately-hard band, but groundwater-heavy zones run far harder. Chlorine is standard, with chloramine in some southern and outer supply areas. The practical upshot: check your zone before buying anything — our zone lookup covers all 28.
What Adelaide homes deal with
Adelaide’s Murray-and-reservoir supply carries the mineral load of its sources: hard water plus the highest TDS of any capital. Hardness scales appliances; TDS drives the famous taste. Chloramine disinfection adds a persistence that basic carbon jugs don’t handle. Reverse osmosis has its strongest Australian case here because it’s the only common filtration that actually reduces dissolved solids.
Which filters, which city
Perth: match treatment to your zone — carbon for taste everywhere, scale management (TAC or softener) in harder zones. Adelaide: under-sink RO for drinking water transforms taste; whole-home scale treatment protects hot water systems. Both cities: if you’re on chloramine, insist on catalytic carbon.
See how every capital ranks in our hardest water in Australia ranking, or compare suppliers with the comparison tool.