Water hardness in Mosta
139 mg/L hard
Tap water in Mosta is hard: 139 mg/L (8.1 gpg · 7.8 °dH · 13.9 °fH).
Source: Water Services Corporation (Malta), Audit Monitoring 2025 (2025-07-08) · data checked 2026-10-22
Malta's tap water is a blend of desalinated seawater (about two-thirds in recent reports) and groundwater from the island's limestone aquifers. The reported hardness is 139.0 mg/L CaCO₃. Expect visible scale in kettles and showers; a scale-control device is worth considering.
The Water Services Corporation reports total hardness in mg/L CaCO₃; Maltese tap water blends reverse-osmosis and groundwater, and the EU Drinking Water Directive sets no limit for hardness.
Water data
| Total hardness | 139 mg/L |
|---|---|
| Utility | Water Services Corporation |
How Mosta compares
- Tap water in Mosta is 12 % softer than the median of the 23 cities we track in Malta (158 mg/L).
- By hardness it ranks 20 of 23 in Malta (1 = hardest); 14 % of these cities have softer water.
- Nearest city with clearly softer water: Ghadira, 8 km away (38 mg/L).
- Nearest city with clearly harder water: Swieqi, 5 km away (177 mg/L).
Ranking of the hardest and softest water in Malta →
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 Mosta
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 8 °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 Mosta water hard or soft?
It is hard: 139 mg/L as CaCO₃ (8.1 gpg, 7.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Mosta safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. The Water Services Corporation reports total hardness in mg/L CaCO₃; Maltese tap water blends reverse-osmosis and groundwater, and the EU Drinking Water Directive sets no limit for hardness.
How many grains per gallon is Mosta water?
8.1 gpg, equal to 7.8 °dH, 13.9 °fH or 139 mg/L calcium carbonate.
What dishwasher salt setting should I use in Mosta?
For 139 mg/L (7.8 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Mosta?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Water Services Corporation (Malta), Audit Monitoring 2025 (2025-07-08). Method: figure published by the water supplier. Water Services Corporation (Malta), Audit Monitoring 2025 · Outdated figure? Tell us