Side-by-Side Water Hardness Calculator

Compare Water Hardness

Analyze real-time PPM, Clark degrees, limescale risk, and dishwasher salt settings between any two UK postcode sectors.

Water Quality Comparison Analysis

Executive Summary: Sector HR9 9 vs Sector SW1A 1

Comparing tap water mineral concentration between Sector HR9 9 (Severn Trent / Hafren Dyfrdwy) and Sector SW1A 1 (Thames Water) reveals a water hardness difference of 125 PPM. Sector HR9 9 has softer water at 150 PPM (Moderately Hard) compared to Sector SW1A 1 at 275 PPM (Hard).

Limescale risk and boiler heating efficiency vary based on these mineral levels. Households in Sector SW1A 1 experience higher heating element degradation and kettle scale accumulation due to elevated calcium carbonate density (275 PPM vs 150 PPM).

For home appliance setup, Bosch dishwasher water softener settings should be calibrated accordingly: Sector HR9 9 requires setting H02 whereas Sector SW1A 1 recommends setting H04.

NP

Sector HR9 9 has 125 PPM LOWER water hardness than Sector SW1A 1

Lower PPM indicates softer water, reduced limescale risk, and lower detergent usage.

Water Metric
Sector HR9 9Outcode: HR9
Sector SW1A 1Outcode: SW1A
Hardness (PPM)
150 PPM
275 PPM
Clark Degrees
10.5 °Clark
19.3 °Clark
Classification
Moderately Hard
Hard
Bosch Salt Setting
H02
H04
Water Supplier
Severn Trent / Hafren Dyfrdwy
Thames Water
Postcodes Covered
9 postcodes
66 postcodes