Wales · County

Water hardness in Cardiff

Average 68 ppm across 36 postcodes and 1 towns.

  • Range 31–109 ppm
  • Towns 1
  • Suppliers Welsh Water (Dwr Cymru)
County average
68
ppm CaCO₃
Slightly Hard
Soft
Moderate
Hard
Very hard
0100200300400+
68
Avg ppm
31
Min ppm
109
Max ppm
36
Postcodes

Water Hardness Across Cardiff

The average water hardness in Cardiff is 68 ppm, classified as slightly hard. Across 36 postcode districts in the Wales region, hardness ranges from 31 ppm to 109 ppm.

Cardiff is served by Welsh Water (Dwr Cymru). With slightly hard water, limescale is unlikely to be a major concern in most homes.

By town

Towns in Cardiff

Sorted by hardness — tap a town for full details.

Town Hardness PPM Level
Cardiff
68
68 ppm Slightly Hard
Suppliers

Water Companies in Cardiff

Companies supplying water to this county.

Welsh Water (Dwr Cymru)

68 ppm Slightly Hard
All postcodes

Postcodes in Cardiff

Every postcode district in the county, sorted by hardness.

Postcode Town Hardness PPM Level
CF39 Porth
109
109 ppm Slightly Hard
CF38 Pontypridd
108
108 ppm Slightly Hard
CF37 Pontypridd
107
107 ppm Slightly Hard
CF36 Porthcawl
106
106 ppm Slightly Hard
CF35 Bridgend
105
105 ppm Slightly Hard
CF34 Maesteg
104
104 ppm Slightly Hard
CF33 Bridgend
103
103 ppm Slightly Hard
CF32 Bridgend
102
102 ppm Slightly Hard
CF64 Penarth
102
102 ppm Slightly Hard
CF31 Bridgend
101
101 ppm Slightly Hard
CF63 Barry
101
101 ppm Slightly Hard
CF62 Barry
100
100 ppm Slightly Hard
CF61 Llantwit Major
99
99 ppm Slightly Hard
CF5 Cardiff
74
74 ppm Slightly Hard
CF3 Cardiff
72
72 ppm Slightly Hard
CF2 Cardiff
71
71 ppm Slightly Hard
CF24 Cardiff
71
71 ppm Slightly Hard
CF23 Cardiff
70
70 ppm Slightly Hard
CF83 Caerphilly
66
66 ppm Slightly Hard
CF82 Hengoed
65
65 ppm Slightly Hard
CF81 Bargoed
64
64 ppm Slightly Hard
CF48 Merthyr Tydfil
40
40 ppm Soft
CF15 Cardiff
39
39 ppm Soft
CF47 Merthyr Tydfil
39
39 ppm Soft
CF14 Cardiff
38
38 ppm Soft
CF46 Treharris
38
38 ppm Soft
CF45 Mountain Ash
37
37 ppm Soft
CF44 Aberdare
36
36 ppm Soft
CF11 Cardiff
35
35 ppm Soft
CF43 Ferndale
35
35 ppm Soft
CF10 Cardiff
34
34 ppm Soft
CF42 Treorchy
34
34 ppm Soft
CF41 Pentre
33
33 ppm Soft
CF40 Tonypandy
32
32 ppm Soft
CF72 Pontyclun
32
32 ppm Soft
CF71 Cowbridge
31
31 ppm Soft

Test Your Water in Cardiff

At 68 ppm on average, your water is slightly hard. A home testing kit lets you verify the exact hardness for your postcode 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

Hard Water Guides

Learn more about water hardness and how to manage it.

What Is Water Hardness? Hard Water Effects Solutions
All counties in Wales · Hardest water areas · Softest water areas · Hard water solutions

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