UK Water Quality Report • 2026 Data

Water Hardness in OX18

Water supply analysis across 5 postcode sectors in OX18 (Thames Water).

Outcode Avg Hardness275 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode OX18

Looking for water hardness metrics in OX18? Water supplied by Thames Water in this outcode registers a baseline average of 275 PPM across 5 distinct postcode sectors.

Water chemistry can fluctuate across supply zones in OX18. The lowest mineral concentration is recorded in sector OX18 1 at 275 PPM, whereas sector OX18 9 experiences higher mineral levels reaching 275 PPM.

Due to the hard water (275 PPM) in OX18, limescale build-up can occur on heating elements, shower heads, and boilers. Setting your dishwasher water softener to the correct level (e.g. Bosch setting H04) is strongly recommended to prevent cloudy glassware and internal scale accumulation. Review the individual postcode sectors below to get precise dishwasher salt settings and limescale recommendations.

Softest Sector in OX18

Lowest mineral concentration

Softest
Sector OX18 1226 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in OX18

Highest mineral concentration

Highest Hardness
Sector OX18 98 Postcodes • Hard
275 PPM19.3 °Clark

All Postcode Sectors in OX18

Select a postcode sector below to view exact water softener salt settings, limescale protection guides, and appliance recommendations.