Water hardness in Rocky Gully
273 mg/L very hard
Tap water in Rocky Gully is very hard: 273 mg/L (15.9 gpg · 15.3 °dH · 27.3 °fH).
Source: Water Corporation, Drinking Water Quality Annual Report, aesthetic tables (great-southern), year to 2025-06 (2025-06) · data checked 2026-10-20
Range across supply zones: 270–280 mg/L.
Australian Drinking Water Guidelines: aesthetic target ≤ 200 mg/L CaCO₃.
Water data
| Total hardness | 273 mg/L |
|---|---|
| Utility | Water Corporation |
How Rocky Gully compares
- Tap water in Rocky Gully is 221 % harder than the median of the 307 cities we track in Australia (85 mg/L).
- By hardness it ranks 14 of 307 in Australia (1 = hardest); 96 % of these cities have softer water.
- In Western Australia it is number 14 of 218 cities; the regional median is 98 mg/L.
- Nearest city with clearly softer water: Frankland, 17 km away (13 mg/L).
Ranking of the hardest and softest water in Australia →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Rocky Gully
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 4 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Rocky Gully water hard or soft?
It is very hard: 273 mg/L as CaCO₃ (15.9 gpg, 15.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rocky Gully safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Australian Drinking Water Guidelines: aesthetic target ≤ 200 mg/L CaCO₃.
How many grains per gallon is Rocky Gully water?
15.9 gpg, equal to 15.3 °dH, 27.3 °fH or 273 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rocky Gully?
For 273 mg/L (15.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Rocky Gully?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Water Corporation, Drinking Water Quality Annual Report, aesthetic tables (great-southern), year to 2025-06 (2025-06). Method: figure published by the water supplier. Water Corporation, Drinking Water Quality Annual Report, aesthetic tables (great-southern), year to 2025-06 · Outdated figure? Tell us