How Welling compares
At 331 mg/L (23.2 °Clark), Welling is 36% above the median of the 411 English towns on this map (243 mg/L). It ranks 29 of 411 for hardness (1 is the hardest).
Welling has very hard water: limescale builds up quickly, so descale often and protect your boiler.
| Value | 331 mg/L calcium carbonate 23.2 °Clark, 18.5 °dH |
|---|---|
| Band | very hard |
| Area | Greater London |
| Population | 41,000 |
| Water company | Thames Water |
| Postcode checked | DA16 3PR (Plumstead) |
| Checked | 21 Oct 2026 |
| From the source | “Hardness (Total) as CaCO3 (mg/l) min 254 mean 331 max 376 | "caCO3AsMgL":"331.0" | "featureName":"Plumstead" | "mapCode":"SLE45" | "detergentIndustryRating":"HARD"” |
Hard water drops a lot of scale when it is heated: in the kettle, the shower head and the element of an immersion heater or washing machine. Chalky rings on taps and spotty glasses are normal.
Set the dishwasher for hard water, dose detergent for your band and descale regularly. If you have a combi boiler, ask about a scale reducer at its next service. Hard water is safe to drink.
At 331 mg/L (23.2 °Clark), Welling is 36% above the median of the 411 English towns on this map (243 mg/L). It ranks 29 of 411 for hardness (1 is the hardest).
As a rule of thumb for very hard water, kettles and shower heads need descaling every three or four weeks. Descale whenever you see scale building up.
No. Hard water carries calcium and magnesium, minerals the body uses. Whether tap water is safe depends on germs and pollutants, which water companies test for, not on hardness.
The water company's figure for Welling is 331 mg/L (23.2 °Clark), which is very hard water. Usually not straight away. Set the dishwasher, dose detergent for your band and descale regularly. Get quotes for a softener only if scale is clearly damaging your boiler or appliances.
Use your water company's postcode checker. Hardness can differ between districts, so check your own postcode, or test with strips or a drop test.
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