Water hardness in Oshkosh
9.9 gpg hard
Tap water in Oshkosh is hard: 9.9 gpg (170 mg/L · 9.5 °dH · 17 °fH).
Source: Wisconsin DNR Drinking Water System portal (Oshkosh Waterworks) (2020) · data checked 2026-10-20
This figure is over 3 years old; hardness may have changed.
Oshkosh treats water from Lake Winnebago at a filtration plant that uses ozone, filtration and activated carbon. The lake lies in a carbonate-rich basin, giving hard water at 170 mg/L CaCO₃. Scale shows up on kettles and shower glass. The figure dates from 2020 and may have changed.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 9.9 gpg |
|---|---|
| Utility | Oshkosh Waterworks |
How Oshkosh compares
- Tap water in Oshkosh is 10 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 625 of 1372 in the United States (1 = hardest); 54 % of these cities have softer water.
- In Wisconsin it is number 316 of 448 cities; the regional median is 14.3 gpg.
- Nearest city with clearly softer water: Winneconne, 15 km away (6.3 gpg).
- Nearest city with clearly harder water: Omro, 14 km away (20.4 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Oshkosh
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| LG | H2 |
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 Oshkosh water hard or soft?
It is hard: 170 mg/L as CaCO₃ (9.9 gpg, 9.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Oshkosh safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Oshkosh water?
9.9 gpg, equal to 9.5 °dH, 17 °fH or 170 mg/L calcium carbonate.
What dishwasher salt setting should I use in Oshkosh?
For 170 mg/L (9.5 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Oshkosh?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Wisconsin DNR Drinking Water System portal (Oshkosh Waterworks) (2020). Method: figure published by the water supplier. Wisconsin DNR Drinking Water System portal (Oshkosh Waterworks) · Outdated figure? Tell us