Hard WaterThames WaterSouth East

Reading Water Hardness Report

Official mineral water quality analysis, local catchment breakdown, appliance salt calibration, and postcode outcode directory for Reading.

Average City Tap Water RatingUpdated 5 September 2025
295PPM (mg/L CaCO3)
Clark Degrees
20.6° Clark
French Scale
29.5°fH
German Scale
16.5°dH

Reading tap water is classified as hard to very hard, averaging 295 PPM. Supplied by Thames Water from River Kennet and River Thames abstractions alongside Berkshire chalk boreholes, the water contains high amounts of dissolved calcium and magnesium. Reading households face stubborn kettle furring, chalky tap crusts, and persistent bath scum. Fitting a water softener or keeping a 1kg tub of food-grade citric acid on hand is standard practice for Berkshire homeowners.

48% harder than the UK national baseline (200 PPM)

Neighbourhood Hydro-Variance

Water hardness across Reading varies by up to 55 PPM between different treatment zones and boreholes.

Softest District265 PPM
Caversham & Mapledurham
Hardest District320 PPM
Tilehurst & Southcote
Supplied by Thames Water under Drinking Water Inspectorate (DWI) regulatory standards.
Local Installer Quote Network

Living in a Hard Water Zone (RG averages 295 PPM)? Compare Approved Local Installers

Get up to 3 free, no-obligation quotes from WRAS-approved water softener installers and heating engineers serving Reading.

Verified Against British Standard BS 7593
WRAS-Approved Water Softeners
100% Free & No Obligation Quotes
Which?-Style Practical Household Advice

Living with Reading Tap Water: Essential Household Guide

Practical calibrations for kitchen appliances, heating systems, and personal care tailored specifically to Reading's water profile.

Kettles & Hot Drinks

Monthly descaling required. Boil one tablespoon of citric acid to dissolve crust before it flakes into morning cuppas.

💡 Pro Tip: Buy food-grade citric acid powder (£5/kg) instead of chemical descaling tablets. One boiled tablespoon cleans the base in 5 minutes with zero lingering odor.
Dishwasher Salt Calibration

Level 4 or 5 (High). Essential to maintain ion-exchange resin bed and prevent cloudy glass etching.

⚙️ Recommended Dial Setting: Level 4–5 (refer to machine manual).
Boiler Efficiency & BS 7593

High scale hazard. Up to 10%–14% fuel efficiency loss without scale protection. In-line scale reducer and BS 7593 inhibitor essential.

🛡️ Compliance: British Standard BS 7593 requires regular chemical inhibitor dosing and annual testing to prevent heat exchanger scale drag.
Bathing, Hair & Sensitive Skin

Hard minerals bind to fatty acids, forming soap curd that strips natural moisture and irritates dry or eczema-prone skin.

🚿 Shower Screens: Use a rubber squeegee after each shower to prevent dissolved calcium from baking into the glass under hot steam.
Common Questions

Frequently Asked Questions about Reading Tap Water

Is tap water hard in Reading?
Yes, Reading tap water is hard, averaging 295 PPM (20.6 Clark degrees). It is heavily mineralised by the surrounding chalk geology of the Thames Valley.
What dishwasher setting should I use in Reading?
Use Level 5 on your dishwasher hardness setting. Check salt levels monthly to prevent glassware etching and cloudiness.
Is a water softener recommended in Reading?
Yes. Many Reading residents install water softeners to protect boilers, eliminate bathroom limescale, and improve skin hydration.
WaterHardness.uk Technical & Water Quality Research Team
Data sourced from Thames Water compliance reports and Drinking Water Inspectorate (DWI) public records.