About WaterHardness.uk
WaterHardness.uk is an independent environmental data platform providing hyper-local water hardness analytics, limescale risk metrics, and appliance calibration guides across 1.7+ million UK postcodes.
Our Mission
Over 60% of the UK receives hard to very hard water. Limescale build-up reduces heating efficiency, shortens boiler lifespans, increases energy bills, and damages dishwashers if salt settings are incorrectly calibrated.
Official water company reports are often hidden inside technical 50-page PDFs. Our mission is to eliminate guesswork by providing instant, postcode-precise water hardness metrics (PPM, Clark Degrees) and actionable appliance setup guides for every UK household.
Data Methodology & Primary Sources
We aggregate, clean, and standardize water quality datasets from official UK regulatory bodies and regional water suppliers:
Drinking Water Inspectorate (DWI)
Data parameters are benchmarked against compliance standards established by the DWI, the official regulator for public water supplies in England and Wales.
Regional Water Suppliers
Water quality metrics are sourced directly from public annual disclosures by Thames Water, Severn Trent, Anglian Water, Scottish Water, Welsh Water (Dŵr Cymru), and regional suppliers.
Water Supply Zone (WSZ) Mapping
Postcode sectors are mapped to specific Water Supply Zones (WSZ) rather than broad local council boundaries to ensure maximum geographic precision.
Appliance Salt Settings Matrix
PPM and Clark degree readings are converted into exact dishwasher water softener settings for major brands including Bosch, Beko, Miele, and Siemens.
Meet the Founder
Nguyễn Hạc Phong
Founder & Data Engineer
WaterHardness.uk was created to solve a common UK household frustration: finding reliable, postcode-exact water hardness metrics without digging through technical 50-page water company reports. As a software engineer specializing in spatial data engineering and programmatic web architecture, I consolidated datasets from over 25 UK water authorities into a single, instant lookup engine.