273mg of limescale minerals in every litre, the median across TW districts
Is Twickenham a hard water area?
Yes. Tap water across the TW postcode area is very hard, the top band on the scale water companies use, with a median of 273 mg/L calcium carbonate. It ranges from 253 mg/L in TW13 to 355 mg/L in TW15, from 20 districts with their own water company reading.
- Soft
- 0 to 60 mg/L
- Moderately soft
- 60 to 120 mg/L
- Slightly hard
- 120 to 180 mg/L
- Hard
- 180 to 200 mg/L
- Very hard
- 200 to 400 mg/L
Hardness by TW district
Hardest first. Hard starts at 180 mg/L, very hard at 250.
| District | Area | mg/L | Hardness |
|---|---|---|---|
| TW15 | Spelthorne | 355 | very hard |
| TW16 | Spelthorne | 346 | very hard |
| TW6 | Hillingdon | 316 | very hard |
| TW10 | Richmond upon Thames | 313 | very hard |
| TW18 | Spelthorne | 303 | very hard |
| TW17 | Spelthorne | 283 | very hard |
| TW20 | Runnymede | 281 | very hard |
| TW9 | Richmond upon Thames | 281 | very hard |
| TW3 | Hounslow | 274 | very hard |
| TW4 | Hounslow | 273 | very hard |
| TW8 | Hounslow | 272 | very hard |
| TW7 | Hounslow | 271 | very hard |
| TW1 | Richmond upon Thames | 270 | very hard |
| TW2 | Richmond upon Thames | 268 | very hard |
| TW5 | Hounslow | 268 | very hard |
| TW19 | Spelthorne | 264 | very hard |
| TW11 | Richmond upon Thames | 263 | very hard |
| TW12 | Richmond upon Thames | 261 | very hard |
| TW14 | Hounslow | 255 | very hard |
| TW13 | Hounslow | 253 | very hard |
What to do about it
Hard water: compare softener quotes
At 273 mg/L most TW homes get their money back on a softener within a few years. A filter will not touch limescale; only a softener does.
- Free quotes
- Local installers
- No obligation
Check your own district first
The area figure is a median. Your district can sit anywhere between 253 and 355 mg/L.
Softener quotes for Twickenham
At 273 mg/L most TW homes get their money back on a softener within a few years. Free quotes from installers covering your postcode.
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Before you buy
- Do I need a water softener?The hardness bands, the symptoms, and when the answer is no
- Best water softener UKHarvey, Kinetico, BWT, Monarch and Water2Buy compared
- Water softener costUnit, fitting and salt, and how long the payback takes
- Installation explainedWhere it goes, the bypass tap, the drain, DIY or plumber
- Harvey vs KineticoThe two premium twin-cylinder brands, side by side
- Softener salt guideTablet, block or granular, and how much you get through
- Salt-free softenersConditioners and electronic descalers, honestly assessed
Questions about Twickenham water
Is Twickenham a hard water area?
Yes. The median hardness across TW postcode districts is 273 mg/L calcium carbonate, which is very hard. 100% of the 20 districts we hold readings for are hard or very hard (180 mg/L and above).
What is the water hardness in Twickenham?
Between 253 and 355 mg/L depending on the district, with a median of 273. The hardest measured district is TW15 at 355 mg/L and the softest is TW13 at 253. Figures come from water company drinking-water tests.
Do I need a water softener in Twickenham?
In most TW homes a softener pays for itself: at 273 mg/L kettles, boilers and showers scale up quickly. Check your own district first, because hardness varies from 253 to 355 within the area.
Hardness as mg/L calcium carbonate from water company drinking-water tests and postcode checkers. See the UK hardness map for every area.