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 RM15 4 vs Sector SW1A 1

Comparing tap water mineral concentration between Sector RM15 4 (Essex and Suffolk Water) and Sector SW1A 1 (Thames Water) reveals a water hardness difference of 45 PPM. Sector SW1A 1 has softer water at 275 PPM (Hard) compared to Sector RM15 4 at 320 PPM (Very Hard).

Limescale risk and boiler heating efficiency vary based on these mineral levels. Households in Sector RM15 4 experience higher heating element degradation and kettle scale accumulation due to elevated calcium carbonate density (320 PPM vs 275 PPM).

For home appliance setup, Bosch dishwasher water softener settings should be calibrated accordingly: Sector RM15 4 requires setting H07 (Max Salt) whereas Sector SW1A 1 recommends setting H04.

NP

Sector SW1A 1 has 45 PPM LOWER water hardness than Sector RM15 4

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

Water Metric
Sector RM15 4Outcode: RM15
Sector SW1A 1Outcode: SW1A
Hardness (PPM)
320 PPM
275 PPM
Clark Degrees
22.4 °Clark
19.3 °Clark
Classification
Very Hard
Hard
Bosch Salt Setting
H07 (Max Salt)
H04
Water Supplier
Essex and Suffolk Water
Thames Water
Postcodes Covered
188 postcodes
66 postcodes