Water hardness

DE1 Derby

Near or below the UK average. Limescale builds slowly.

At 177 ppm, Derby ranks near the UK's softest water areas — compare it against the hardest areas.

Moderately Hard 177 ppm East Midlands Severn Trent Water
Your reading
177
parts per million
Soft
Moderate
Hard
Very hard
0100200300400+

What this means for your home

Based on 177 ppm in Derby (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
£10–17
per year
Worth it?
No
at 177 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 Derby?

A verdict and running-cost estimate based on DE1's 177 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 15.1 days
Salt running cost
£10–17
per year (~36 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 177 ppm: slight: minor descaling extends kettle/boiler life. Sized for a 4-person home; regenerates roughly every 15 days (estimate). Figures are conservative estimates and vary with household size and usage.

Test Your Water in Derby

At 177 ppm, your water is moderately hard. A home testing kit lets you verify the exact hardness and check for other contaminants.

TESPERT 16-in-1 Water Testing Kit

From ~£10

Home water test strips that check hardness, pH, chlorine, lead, and 12 other parameters. Results in around 60 seconds. 125 strips per pack.

View on Amazon
Water quality details

Hardness data for DE1

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

Hardness measurements

Parts per million (ppm CaCO₃)177
Degrees Clark (°Clark)12.4
Degrees French (°fH)17.7
Degrees German (°dH)9.9
Calcium (mg/L Ca²⁺)71

Supplier and area

Water supplier Severn Trent Water
Region East Midlands
County Derbyshire
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 Derby

DE3
Derby
179ppm
Moderately Hard
FAQ

Common questions about DE1

What is the water hardness in DE1 Derby?
The water in DE1 Derby has a hardness level of 177 ppm (parts per million) calcium carbonate, classified as moderately hard. This is 30 ppm below the UK national average of 207 ppm.
Which water company supplies DE1?
DE1 Derby is supplied by Severn Trent Water. Severn Trent Water serves the East Midlands region.
Is the water in DE1 safe to drink?
Yes. Moderately Hard water at 177 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 DE1?
At 177 ppm, the water in DE1 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 177 ppm water hardness mean?
177 ppm means there are 177 parts per million of calcium carbonate dissolved in the water. This is equivalent to 12.4 Clark degrees, 9.9 German degrees, or 17.7 French degrees. Water above 180 ppm is generally considered hard.
What size water softener do I need in DE1?
For a typical 4-person home at 177 ppm, a 24,000 grain softener is a sensible size. It would regenerate roughly every 15.1 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 DE1?
At 177 ppm, expect to use about 36 kg of salt a year, costing roughly £10–£17/year. Water is soft to moderate, so limescale and soap costs are low and a softener rarely pays back.

Get DE1 Water Updates

We'll notify you when Severn Trent Water reports changes to water hardness in your area.

Check another postcode

Compare hardness across areas before moving or buying a softener.