Water Hardness Breakdown for Sector GU21 4
Serving the community across sector GU21 4, mains tap water is supplied by Affinity Water. Across the 258 postcodes within this distribution boundary, the baseline water hardness currently averages 305 PPM, falling into the very hard threshold.
With an intense mineral load of 305 PPM (21.3° Clark), households in GU21 4 face rapid limescale deposition. Dissolved calcium and magnesium leave thick chalky residue on shower screens, aerators, and heating elements while reducing central heating boiler efficiency by up to 18% – 25%+.
Water distributed by Affinity Water in this southeastern/eastern catchment is predominantly drawn from underground chalk and limestone aquifers. As rainwater filters through deep subterranean chalk strata, it naturally dissolves high concentrations of calcium bicarbonate, resulting in the consistent 305 PPM profile recorded across sector GU21 4.
In everyday household use, calcium and magnesium ions in 305 PPM water bind with soaps, producing chalky bathroom residue and scum on your morning cuppa. In sector GU21 4, washing laundry or dishware requires +50% extra detergent alongside dedicated limescale inhibitors. For personal grooming, individuals with dry skin or eczema sensitivity may experience skin tightness after showers in this very hard water environment.
Calibrating appliance water softening systems in GU21 4 prevents etched glassware and heating element burnouts. Based on Affinity Water's official 305 PPM rating, Bosch dishwashers should be set to H06 / H07. Consult the interactive equipment guide below for custom brand settings across all 258 postcodes.