Water hardness in Glasgow
16 mg/L soft
Tap water in Glasgow is soft: 16 mg/L (0.9 gpg · 0.9 °dH · 1.6 °fH).
Source: Scottish Water - Water Hardness Data 2024 (regulatory supply zones) (2024) · data checked 2026-10-22
Range across supply zones: 16–20 mg/L.
12 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| mg/L | mg/L | ||
|---|---|---|---|
| Balmore C5 North (G21, G22) | 20 | 20 | soft |
| Balmore C5 South (G33, G34) | 19 | 19 | soft |
| Balmore Castlemilk (G44, G45) | 19 | 19 | soft |
| Milngavie C3 (G4, G31) | 16 | 16 | soft |
| Milngavie C4 (G32, G40) | 16 | 16 | soft |
| Milngavie M1 (G20, G23) | 16 | 16 | soft |
| Milngavie M2 (G5, G41, G43) | 16 | 16 | soft |
| Milngavie M3 (G1, G2, G3, G51) | 16 | 16 | soft |
| Milngavie M4c (G13) | 16 | 16 | soft |
| Milngavie M4d (G11, G12, G14) | 16 | 16 | soft |
| Milngavie M5 Drumchapel North (G15) | 16 | 16 | soft |
| Milngavie M5 Drumchapel South (G52, G53) | 16 | 16 | soft |
Glasgow's water comes from Loch Katrine, piped about 24 miles to Milngavie, and is supplied by Scottish Water. The figure is from 2024 data. The median across its 12 supply zones is 16.0 mg/L CaCO₃ (range 15.7 to 19.8 mg/L), so it depends on your street's zone. Rain falling on hard, slow-draining upland rock picks up little calcium, which keeps the water soft; the water is very soft, so limescale is rarely a problem and a softener is not needed; check detergent dosing, as soft water needs less.
UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
Water data
| Total hardness | 16 mg/L |
|---|---|
| Calcium (mg/L) | 5.29 |
| Magnesium (mg/L) | 0.6 |
| Utility | Scottish Water |
How Glasgow compares
- Tap water in Glasgow is 91 % softer than the median of the 471 cities we track in the United Kingdom (185 mg/L).
- By hardness it ranks 468 of 471 in the United Kingdom (1 = hardest); 1 % of these cities have softer water.
- In Scotland it is number 21 of 24 cities; the regional median is 31 mg/L.
- Nearest city with clearly softer water: Tarbert, 72 km away (8 mg/L).
- Nearest city with clearly harder water: Alexandria, 25 km away (29 mg/L).
Ranking of the hardest and softest water in the United Kingdom →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Glasgow
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Glasgow water hard or soft?
It is soft: 16 mg/L as CaCO₃ (0.9 gpg, 0.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Glasgow safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
How many grains per gallon is Glasgow water?
0.9 gpg, equal to 0.9 °dH, 1.6 °fH or 16 mg/L calcium carbonate.
What dishwasher salt setting should I use in Glasgow?
For 16 mg/L (0.9 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Glasgow?
No. With soft water a softener adds nothing.
Source
Source: Scottish Water - Water Hardness Data 2024 (regulatory supply zones) (2024). Method: figure published by the water supplier. Scottish Water - Water Hardness Data 2024 (regulatory supply zones) · Outdated figure? Tell us