UK Water Quality Report • 2026 Data

Water Hardness in GY5

Water supply analysis across 1 postcode sectors in GY5 (Guernsey Water).

Outcode Avg Hardness140 PPMModerately Hard Water
Regional Quality Overview

Water Supply Analysis: Outcode GY5

Analyzing water quality disclosures across all 1 postcode sectors in outcode GY5 reveals an average water hardness of 140 PPM (Moderately Hard Water). Public water supply across this area is managed by Guernsey Water, responsible for treating and delivering water to residential households.

Water chemistry can fluctuate across supply zones in GY5. The lowest mineral concentration is recorded in sector GY5 7 at 140 PPM, whereas sector GY5 7 experiences higher mineral levels reaching 140 PPM.

Due to the moderately hard water (140 PPM) in GY5, 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 H01) 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 GY5

Lowest mineral concentration

Softest
Sector GY5 7304 Postcodes • Slightly Hard
140 PPM9.8 °Clark

Hardest Sector in GY5

Highest mineral concentration

Highest Hardness
Sector GY5 7304 Postcodes • Slightly Hard
140 PPM9.8 °Clark

All Postcode Sectors in GY5

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