London vs Cardiff
Water hardness comparison — how the two cities differ and what it means for your home.
HarderFull London data →
London
united kingdom
277mg/L
Very Hard Water
19.39°e
Very Hard
Base Unit (CaCO3): 277 mg/LLocal Unit
Cardiff
united kingdom
115mg/L
Moderately Hard Water
8.05°e
Medium
Base Unit (CaCO3): 115 mg/LLocal Unit
Side-by-Side Impact
| Impact Area | London | Cardiff |
|---|---|---|
| Limescale buildup | Rapid — visible within weeks | Minimal |
| Boiler/heating risk | Annual descaling required | Low risk |
| Dishwasher salt setting | Max salt setting (5–7) | Low setting (1–2) |
| Skin & hair impact | High eczema/dry skin risk | Low risk |
| Detergent usage | +30–40% more detergent | Standard dose |
Key Findings
Hardness Difference: 162 mg/L
London is significantly harder than Cardiff — a difference that has major household implications. Appliances, boiler warranties, and detergent costs will differ substantially.
Moving from Cardiff to London?
If you're relocating from Cardiff to London, expect visible limescale on taps and shower heads within weeks. You'll need to recalibrate your dishwasher's salt setting, increase kettle descaling frequency, and check your boiler warranty requirements. A shower filter and under-sink scale inhibitor are worth considering immediately.