Water hardness

CR9 Croydon

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

At 301 ppm, Croydon sits among the UK's hardest water areas — compare it against the softest areas.

Very Hard 301 ppm London South East Water
Your reading
301
parts per million
Soft
Moderate
Hard
Very hard
0100200300400+

What this means for your home

Based on 301 ppm in Croydon (very hard water).

  • Heavy limescale requiring frequent descaling
  • Blocked showerheads and reduced water flow
  • Substantially higher energy bills from boiler scale
  • Dry, itchy skin and lifeless hair
  • White crusty deposits on taps and surfaces
  • Reduced lifespan of washing machines and dishwashers
Heat loss
12%
Heavy scaling
Softener salt
£17–30
per year
Worth it?
Yes
at 301 ppm
Suggested for very 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 Croydon?

A verdict and running-cost estimate based on CR9's 301 ppm reading, for a typical 4-person household.

Softener recommended

Water is hard to very hard, so appliance, scale and soap savings typically pay back a softener within a few years.

Recommended size
24k
grain capacity, regenerates ~every 8.9 days
Salt running cost
£17–30
per year (~62 kg salt)
Limescale
12%
est. heater efficiency loss. Heavy scaling
Soap saving
High
Large saving: many homes cut soap, shampoo and detergent use by up to half.

Appliance impact at 301 ppm: significant: elements fur up, expect earlier failures. Sized for a 4-person home; regenerates roughly every 9 days (estimate). Figures are conservative estimates and vary with household size and usage.

Water quality details

Hardness data for CR9

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

Hardness measurements

Parts per million (ppm CaCO₃)301
Degrees Clark (°Clark)21.1
Degrees French (°fH)30.1
Degrees German (°dH)16.9
Calcium (mg/L Ca²⁺)121

Supplier and area

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

Use the hardness checker to find your water hardness level so you can set the correct settings on your dishwasher, coffee maker, and washing machine.

Nearby

Other areas near Croydon

CR8
Purley
300ppm
Hard
FAQ

Common questions about CR9

What is the water hardness in CR9 Croydon?
The water in CR9 Croydon has a hardness level of 301 ppm (parts per million) calcium carbonate, classified as very hard. This is 94 ppm above the UK national average of 207 ppm.
Which water company supplies CR9?
CR9 Croydon is supplied by South East Water. South East Water serves the London region.
Is the water in CR9 safe to drink?
Yes. Very Hard water at 301 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 CR9?
For very hard water at 301 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 301 ppm water hardness mean?
301 ppm means there are 301 parts per million of calcium carbonate dissolved in the water. This is equivalent to 21.1 Clark degrees, 16.9 German degrees, or 30.1 French degrees. Water above 180 ppm is generally considered hard.
What size water softener do I need in CR9?
For a typical 4-person home at 301 ppm, a 24,000 grain softener is a sensible size. It would regenerate roughly every 8.9 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 CR9?
At 301 ppm, expect to use about 62 kg of salt a year, costing roughly £17–£30/year. Water is hard to very hard, so appliance, scale and soap savings typically pay back a softener within a few years.

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