Water hardness in Trets
16.5 °fH hard
Tap water in Trets is hard: 16.5 °fH (165 mg/L · 9.6 gpg · 9.2 °dH).
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 13110 (2026-08) · data checked 2026-10-19
In Trets (Bouches-du-Rhône), the ARS health-control record (SISE-Eaux, commune 13110) reports a hardness of 165 mg/L CaCO₃, which is hard water. The measurement dates from August 2026 and the listed service is Société des Eaux de Marseille.
TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
Water data
| Total hardness | 16.5 °fH |
|---|---|
| Utility | Societe Des Eaux De Marseille |
How Trets compares
- Tap water in Trets is 31 % softer than the median of the 33641 cities we track in France (23.9 °fH).
- By hardness it ranks 23044 of 33641 in France (1 = hardest); 31 % of these cities have softer water.
- In Bouches-du-Rhône it is number 116 of 118 cities; the regional median is 22.4 °fH.
- Nearest city with clearly softer water: Collobrières, 56 km away (10.2 °fH).
- Nearest city with clearly harder water: Saint-Zacharie, 7 km away (30.9 °fH).
Ranking of the hardest and softest water in France →
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 Trets
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 9 °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 Trets water hard or soft?
It is hard: 165 mg/L as CaCO₃ (9.6 gpg, 9.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Trets safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
How many grains per gallon is Trets water?
9.6 gpg, equal to 9.2 °dH, 16.5 °fH or 165 mg/L calcium carbonate.
What dishwasher salt setting should I use in Trets?
For 165 mg/L (9.2 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Trets?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 13110 (2026-08). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 13110 · Outdated figure? Tell us