Water hardness

SO51 Romsey

Near or below the UK average. Limescale builds slowly.

At 164 ppm, Romsey ranks near the UK's softest water areas — compare it against the hardest areas.

Moderately Hard 164 ppm South East Severn Trent Water
Your reading
164
parts per million
Soft
Moderate
Hard
Very hard
0100200300400+

What this means for your home

Based on 164 ppm in Romsey (moderately hard water).

  • Noticeable limescale buildup in kettles and boilers
  • Soap may not lather as easily
  • Showerhead may need descaling periodically
  • Slight film on glassware after washing
Heat loss
4%
Light scaling
Softener salt
£9–16
per year
Worth it?
No
at 164 ppm
Suggested for moderately hard water
Filter jug (optional)
Mainly a taste preference, limescale won't be a real issue here.
From £20
Maintenance habits
Routine descaling once or twice a year is plenty.
Free
Softening

Should you soften the water in Romsey?

A verdict and running-cost estimate based on SO51's 164 ppm reading, for a typical 4-person household.

Softener optional

Water is soft to moderate, so limescale and soap costs are low and a softener rarely pays back.

Recommended size
24k
grain capacity, regenerates ~every 16.3 days
Salt running cost
£9–16
per year (~34 kg salt)
Limescale
4%
est. heater efficiency loss. Light scaling
Soap saving
Low
Some saving: expect to use slightly less soap and detergent.

Appliance impact at 164 ppm: slight: minor descaling extends kettle/boiler life. Sized for a 4-person home; regenerates roughly every 16 days (estimate). Figures are conservative estimates and vary with household size and usage.

Water quality details

Hardness data for SO51

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

Hardness measurements

Parts per million (ppm CaCO₃)164
Degrees Clark (°Clark)11.5
Degrees French (°fH)16.4
Degrees German (°dH)9.2
Calcium (mg/L Ca²⁺)66

Supplier and area

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

Enter your postcode and pick a timeframe to see your area's measured water quality including hardness, with a downloadable PDF report.

Nearby

Other areas near Romsey

SO50
Eastleigh
163ppm
Moderately Hard
SO52
Southampton
165ppm
Moderately Hard
SO53
Eastleigh
166ppm
Moderately Hard
FAQ

Common questions about SO51

What is the water hardness in SO51 Romsey?
The water in SO51 Romsey has a hardness level of 164 ppm (parts per million) calcium carbonate, classified as moderately hard. This is 43 ppm below the UK national average of 207 ppm.
Which water company supplies SO51?
SO51 Romsey is supplied by Severn Trent Water. Severn Trent Water serves the South East region.
Is the water in SO51 safe to drink?
Yes. Moderately Hard water at 164 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 SO51?
At 164 ppm, the water in SO51 is moderately hard and unlikely to cause significant issues. A jug filter can improve taste, but a water softener is generally not necessary.
What does 164 ppm water hardness mean?
164 ppm means there are 164 parts per million of calcium carbonate dissolved in the water. This is equivalent to 11.5 Clark degrees, 9.2 German degrees, or 16.4 French degrees. Water above 180 ppm is generally considered hard.
What size water softener do I need in SO51?
For a typical 4-person home at 164 ppm, a 24,000 grain softener is a sensible size. It would regenerate roughly every 16.3 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 SO51?
At 164 ppm, expect to use about 34 kg of salt a year, costing roughly £9–£16/year. Water is soft to moderate, so limescale and soap costs are low and a softener rarely pays back.

Your Romsey water action plan

Enter your email for the short list of things worth doing at 164 ppm, and the upgrades you can safely ignore.

Check another postcode

Compare hardness across areas before moving or buying a softener.