Cardiff · Wales

Is Cardiff water hard or soft?

Slightly Hard at 68 ppm · 36 postcode districts

  • Supplier Welsh Water (Dwr Cymru)
  • County Cardiff
  • Postcodes 36
Area average
68
ppm CaCO₃
Slightly Hard
Soft
Moderate
Hard
Very hard
0100200300400+

The average water hardness in Cardiff is 68 ppm, classified as slightly hard. Cardiff is served by Welsh Water (Dwr Cymru), covering 36 postcode districts across Cardiff in the Wales region.

Hardness varies across the area — see the table below for a breakdown by postcode district.

By postcode

Water Hardness by Postcode in Cardiff

Sorted by hardness — tap a postcode for full details.

Postcode Water Company Hardness PPM Level
CF39 Welsh Water (Dwr Cymru)
109
109 ppm Slightly Hard
CF38 Welsh Water (Dwr Cymru)
108
108 ppm Slightly Hard
CF37 Welsh Water (Dwr Cymru)
107
107 ppm Slightly Hard
CF36 Welsh Water (Dwr Cymru)
106
106 ppm Slightly Hard
CF35 Welsh Water (Dwr Cymru)
105
105 ppm Slightly Hard
CF34 Welsh Water (Dwr Cymru)
104
104 ppm Slightly Hard
CF33 Welsh Water (Dwr Cymru)
103
103 ppm Slightly Hard
CF32 Welsh Water (Dwr Cymru)
102
102 ppm Slightly Hard
CF64 Welsh Water (Dwr Cymru)
102
102 ppm Slightly Hard
CF31 Welsh Water (Dwr Cymru)
101
101 ppm Slightly Hard
CF63 Welsh Water (Dwr Cymru)
101
101 ppm Slightly Hard
CF62 Welsh Water (Dwr Cymru)
100
100 ppm Slightly Hard
CF61 Welsh Water (Dwr Cymru)
99
99 ppm Slightly Hard
CF5 Welsh Water (Dwr Cymru)
74
74 ppm Slightly Hard
CF3 Welsh Water (Dwr Cymru)
72
72 ppm Slightly Hard
CF2 Welsh Water (Dwr Cymru)
71
71 ppm Slightly Hard
CF24 Welsh Water (Dwr Cymru)
71
71 ppm Slightly Hard
CF23 Welsh Water (Dwr Cymru)
70
70 ppm Slightly Hard
CF83 Welsh Water (Dwr Cymru)
66
66 ppm Slightly Hard
CF82 Welsh Water (Dwr Cymru)
65
65 ppm Slightly Hard
CF81 Welsh Water (Dwr Cymru)
64
64 ppm Slightly Hard
CF48 Welsh Water (Dwr Cymru)
40
40 ppm Soft
CF15 Welsh Water (Dwr Cymru)
39
39 ppm Soft
CF47 Welsh Water (Dwr Cymru)
39
39 ppm Soft
CF14 Welsh Water (Dwr Cymru)
38
38 ppm Soft
CF46 Welsh Water (Dwr Cymru)
38
38 ppm Soft
CF45 Welsh Water (Dwr Cymru)
37
37 ppm Soft
CF44 Welsh Water (Dwr Cymru)
36
36 ppm Soft
CF11 Welsh Water (Dwr Cymru)
35
35 ppm Soft
CF43 Welsh Water (Dwr Cymru)
35
35 ppm Soft
CF10 Welsh Water (Dwr Cymru)
34
34 ppm Soft
CF42 Welsh Water (Dwr Cymru)
34
34 ppm Soft
CF41 Welsh Water (Dwr Cymru)
33
33 ppm Soft
CF40 Welsh Water (Dwr Cymru)
32
32 ppm Soft
CF72 Welsh Water (Dwr Cymru)
32
32 ppm Soft
CF71 Welsh Water (Dwr Cymru)
31
31 ppm Soft
Suppliers

Water Companies Serving Cardiff

Tap for full coverage area and hardness data.

Welsh Water (Dwr Cymru)

68 ppm Slightly Hard

Water Hardness Guides

Learn more about water hardness and how to manage it.

What Is Water Hardness? Effects Solutions Water Softeners Limescale Removal

Test Your Water in Cardiff

At 68 ppm, your water is slightly hard. A home testing kit lets you verify the exact hardness and check for other contaminants.

SJ WAVE 16-in-1 Water Testing Kit

From ~£10

Quick home water test strips — checks hardness, pH, chlorine, lead, and 12 other parameters. Results in 60 seconds. 100 strips per pack.

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