Water hardness in Corpus Christi
13.8 gpg very hard
Tap water in Corpus Christi is very hard: 13.8 gpg (236 mg/L · 13.2 °dH · 23.6 °fH).
Source: City of Corpus Christi 2025 Water Quality Report (2025) · data checked 2026-10-19
The City of Corpus Christi's 2025 report gives total hardness as CaCO3 of 236 mg/L (13.8 gpg), one citywide figure with no zone split. This is very hard water. Earlier city reports we checked were close to this value, so it is not a one-year swing. Scale builds quickly on water heaters.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 13.8 gpg |
|---|---|
| Utility | City of Corpus Christi Water Department |
How Corpus Christi compares
- Tap water in Corpus Christi is 52 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 414 of 1372 in the United States (1 = hardest); 70 % of these cities have softer water.
- In Texas it is number 16 of 60 cities; the regional median is 8.6 gpg.
- Nearest city with clearly softer water: Rockport, 42 km away (10.5 gpg).
Ranking of the hardest and softest water in the United States →
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 Corpus Christi
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| 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 Corpus Christi water hard or soft?
It is very hard: 236 mg/L as CaCO₃ (13.8 gpg, 13.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Corpus Christi 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 Corpus Christi water?
13.8 gpg, equal to 13.2 °dH, 23.6 °fH or 236 mg/L calcium carbonate.
What dishwasher salt setting should I use in Corpus Christi?
For 236 mg/L (13.2 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Corpus Christi?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: City of Corpus Christi 2025 Water Quality Report (2025). Method: figure published by the water supplier. City of Corpus Christi 2025 Water Quality Report · Outdated figure? Tell us