294mg of limescale minerals in every litre, the median across SE districts
Is South East London a hard water area?
Yes. Tap water across the SE postcode area is very hard, the top band on the scale water companies use, with a median of 294 mg/L calcium carbonate. It ranges from 248 mg/L in SE26 to 355 mg/L in SE12, from 28 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 SE district
Hardest first. Hard starts at 180 mg/L, very hard at 250.
| District | Area | mg/L | Hardness |
|---|---|---|---|
| SE12 | Lewisham | 355 | very hard |
| SE7 | Greenwich | 355 | very hard |
| SE20 | Bromley | 334 | very hard |
| SE16 | Southwark | 333 | very hard |
| SE28 | Greenwich | 331 | very hard |
| SE6 | Lewisham | 331 | very hard |
| SE22 | Southwark | 330 | very hard |
| SE21 | Southwark | 318 | very hard |
| SE4 | Lewisham | 312 | very hard |
| SE24 | Lambeth | 311 | very hard |
| SE27 | Lambeth | 308 | very hard |
| SE23 | Lewisham | 304 | very hard |
| SE25 | Croydon | 304 | very hard |
| SE2 | Greenwich | 295 | very hard |
| SE17 | Southwark | 293 | very hard |
| SE19 | Croydon | 292 | very hard |
| SE3 | Greenwich | 291 | very hard |
| SE5 | Southwark | 290 | very hard |
| SE1 | Southwark | 290 | very hard |
| SE10 | Greenwich | 282 | very hard |
| SE13 | Lewisham | 277 | very hard |
| SE14 | Lewisham | 269 | very hard |
| SE11 | Lambeth | 268 | very hard |
| SE8 | Lewisham | 260 | very hard |
| SE18 | Greenwich | 256 | very hard |
| SE9 | Greenwich | 254 | very hard |
| SE15 | Southwark | 251 | very hard |
| SE26 | Lewisham | 248 | hard |
What to do about it
Hard water: compare softener quotes
At 294 mg/L most SE 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 248 and 355 mg/L.
Softener quotes for South East London
At 294 mg/L most SE homes get their money back on a softener within a few years. Free quotes from installers covering your postcode.
Request a free assessment and we'll come back to you with local installer options for your area.
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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 South East London water
Is South East London a hard water area?
Yes. The median hardness across SE postcode districts is 294 mg/L calcium carbonate, which is very hard. 100% of the 28 districts we hold readings for are hard or very hard (180 mg/L and above).
What is the water hardness in South East London?
Between 248 and 355 mg/L depending on the district, with a median of 294. The hardest measured district is SE12 at 355 mg/L and the softest is SE26 at 248. Figures come from water company drinking-water tests.
Do I need a water softener in South East London?
In most SE homes a softener pays for itself: at 294 mg/L kettles, boilers and showers scale up quickly. Check your own district first, because hardness varies from 248 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.