Water hardness

PO31 Cowes

Harder than the UK average. Expect visible limescale on kettles and taps.

At 238 ppm, Cowes sits among the UK's hardest water areas — compare it against the softest areas.

Hard 238 ppm South East Portsmouth Water
Your reading
238
parts per million
Soft
Moderate
Hard
Very hard
0100200300400+

What this means for your home

Based on 238 ppm in Cowes (hard water).

  • Significant limescale buildup in kettles, pipes and boilers
  • Soap scum on shower screens and taps
  • Higher energy bills from scale in heating elements
  • Dry skin and dull hair after washing
  • White residue on dishes and glassware
Heat loss
8%
Moderate scaling
Softener salt
£14–23
per year
Worth it?
Yes
at 238 ppm
Suggested for hard water
Whole-house water softener
Best long-term protection for boilers and pipes.
From £600 installed
Shower head filter
A simple first step for limescale on tiles and glass.
From £25
Filter jug or under-sink
Improves taste and reduces kettle scale.
From £20
Softening

Should you soften the water in Cowes?

A verdict and running-cost estimate based on PO31's 238 ppm reading, for a typical 4-person household.

Softener recommended

Hardness is moderate to hard, so a softener cuts scale and soap use and usually pays back over its lifetime.

Recommended size
24k
grain capacity, regenerates ~every 11.3 days
Salt running cost
£14–23
per year (~48 kg salt)
Limescale
8%
est. heater efficiency loss. Moderate scaling
Soap saving
Moderate
Noticeable saving: soaps lather more easily, cutting detergent use.

Appliance impact at 238 ppm: noticeable: boiler/dishwasher life cut without descaling. Sized for a 4-person home; regenerates roughly every 11 days (estimate). Figures are conservative estimates and vary with household size and usage.

Water quality details

Hardness data for PO31

Sourced from Portsmouth Water's published water-quality reports and public records.

Hardness measurements

Parts per million (ppm CaCO₃)238
Degrees Clark (°Clark)16.7
Degrees French (°fH)23.8
Degrees German (°dH)13.3
Calcium (mg/L Ca²⁺)95

Supplier and area

Water supplier Portsmouth Water
Region South East
County Hampshire
Hardness band Hard
UK average 207 ppm
Visit Portsmouth Water page
Official source
Portsmouth Water water-hardness report

Find your supply zone on the map, then download the matching PDF to read your average water hardness and quality results.

Nearby

Other areas near Cowes

PO30
Newport
237ppm
Hard
PO32
East Cowes
239ppm
Hard
PO33
Ryde
240ppm
Hard
FAQ

Common questions about PO31

What is the water hardness in PO31 Cowes?
The water in PO31 Cowes has a hardness level of 238 ppm (parts per million) calcium carbonate, classified as hard. This is 31 ppm above the UK national average of 207 ppm.
Which water company supplies PO31?
PO31 Cowes is supplied by Portsmouth Water. Portsmouth Water serves the South East region.
Is the water in PO31 safe to drink?
Yes. Hard water at 238 ppm is safe to drink. Water hardness affects taste and can cause limescale, but it is not a health risk. In fact, hard water contains beneficial minerals like calcium and magnesium.
How can I reduce water hardness in PO31?
For hard water at 238 ppm, a whole-house water softener is the most effective solution. You can also use a jug filter for drinking water, descaling products for appliances, and a shower filter for better skin and hair.
What does 238 ppm water hardness mean?
238 ppm means there are 238 parts per million of calcium carbonate dissolved in the water. This is equivalent to 16.7 Clark degrees, 13.3 German degrees, or 23.8 French degrees. Water above 180 ppm is generally considered hard.
What size water softener do I need in PO31?
For a typical 4-person home at 238 ppm, a 24,000 grain softener is a sensible size. It would regenerate roughly every 11.3 days. Larger households or higher daily use need a bigger unit. These figures are conservative estimates.
How much does it cost to run a water softener in PO31?
At 238 ppm, expect to use about 48 kg of salt a year, costing roughly £14–£23/year. Hardness is moderate to hard, so a softener cuts scale and soap use and usually pays back over its lifetime.

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