Official Supplier Data: Portsmouth Water • DWI & BS 7593 Standards
Water Hardness in PO11
Official water quality verdict for outcode PO11: classified as Hard Water (250 PPM), supplied and treated by Portsmouth Water across 3 sectors.
Rating: Hard Water250 PPM • 17.5° ClarkSupplier: Portsmouth Water+25% above UK average
Outcode Mean Hardness250 PPM17.5° Clark • Hard Water25.0°fH • 14.0°dH
Outcode PO11 Household Water Quality Verdict & Practical Advice
Domestic tap water in outcode PO11 is officially classified as hard water, averaging 250 PPM (mg/L CaCO₃) or 17.5° Clark, supplied and treated by Portsmouth Water across all 3 postcode sectors (472 postcodes). Readings range from 250 PPM (PO11 0) to 250 PPM (PO11 9) with consistent mineral levels throughout.
☕ Kettle & Tea Quality:
Rapid limescale buildup in kettles with floating scum on your cuppa. Descale monthly using white vinegar or food-grade citric acid.
🚿 Skin & Bathing:
High calcium levels can aggravate dry skin & eczema sensitivity. Soap lathers less easily, often leaving a tight feeling after hot showers.
🍽️ Appliances & Salt:
Keep water softener salt topped up and calibrate dishwashers to H04 – H05. Protect combi boiler heat exchangers under BS 7593.
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vs. UK Benchmark+25% Hardervs 200 PPM national average
Serving 472 homes and businesses across outcode PO11, mains tap water supplied by Portsmouth Water registers an average mineral density of 250 PPM (25.0°fH / 14.0°dH). Rated as hard water, local water hardness determines how well laundry detergents lather, the rate of scale accumulation in combi boilers, and whether sensitive skin or eczema flares up after showers.
Water hardness is remarkably consistent across all 3 sectors of PO11, with readings holding steady at 250 PPM from PO11 0 through to PO11 9. This uniform profile means every household on the Portsmouth Water network in this zone shares the same appliance settings and kettle descaling routine.
Treated in strict compliance with Drinking Water Inspectorate (DWI) standards, tap water in PO11 maintains an average mineral density of 250 PPM, ensuring consistent municipal distribution and wholesome tap drinking water from Portsmouth Water.
With tap water averaging 250 PPM in outcode PO11, proactive limescale prevention is essential. Expect rapid limescale buildup in kettles—monthly descaling with white vinegar or food-grade citric acid crystals keeps the heating base efficient and stops chalky flakes falling into your tea. Combi boiler heat exchangers are also susceptible to scale encrustation, which can increase annual gas heating bills by 10% – 15% without inline scale protection under British Standard BS 7593.
Estimated Annual Household Financial Impact
Limescale & Appliance Operating Costs in Outcode PO11
Based on 250 PPM mineral saturation (Hard Water), operating heating appliances across PO11's 472 households carries distinct annual economic consequences:
Extra Combi Boiler Gas Cost£130 – £190
Thermal heating transfer resistance caused by 1mm–1.5mm calcium carbonate build-up on heat exchangers.
Dishwasher Salt Requirement10 – 14 kg
Essential ion-exchange resin bed regeneration salt required to avoid glass clouding and element burnout.
Tap water throughout outcode PO11 is supplied from a unified distribution network managed by Portsmouth Water. With all 3 sectors presenting an identical mineral concentration of 250 PPM, households across all 472 postcodes share uniform limescale risk profiles and identical appliance salt calibrations (H04 – H05).
Frequently Asked Questions: Water in Outcode PO11
Q: What is the average water hardness in outcode PO11?
Tap water across outcode PO11 averages 250 PPM (mg/L), which equals 17.5° Clark, 25.0°fH, or 14.0°dH. It is officially classified as hard water water supplied by Portsmouth Water.
Q: Is water in PO11 harder than the UK national average?
The UK baseline average is approximately 200 PPM. At 250 PPM, water in outcode PO11 is 25% harder than the national benchmark.
Q: What dishwasher salt setting is recommended for PO11?
For Bosch, Siemens, and Neff dishwashers in outcode PO11 (250 PPM), the recommended softener setting is H04 – H05.
Q: Who manages the municipal water supply in outcode PO11?
Public tap water infrastructure across all 3 sectors in outcode PO11 is distributed and monitored by Portsmouth Water.
All Postcode Sectors in PO11
Select a postcode sector below to view exact water softener salt settings, limescale protection guides, and appliance recommendations.