154mg of limescale minerals in every litre, the median across GU districts
Is Guildford a hard water area?
No. Tap water across the GU postcode area is moderately hard, with some scale over time but rarely enough to need a softener, with a median of 154 mg/L calcium carbonate. It ranges from 75 mg/L in GU25 to 287 mg/L in GU7, from 23 districts with their own water company reading and 15 estimated from the area.
- Soft
- 0 to 60 mg/L
- Moderately soft
- 60 to 120 mg/L
- Slightly hard
- 120 to 180 mg/L
- Hard
- 180 to 200 mg/L
- Very hard
- 200 to 400 mg/L
Hardness by GU district
Hardest first. Hard starts at 180 mg/L, very hard at 250. Districts marked with an asterisk take the area's median rather than a reading of their own.
| District | Area | mg/L | Hardness |
|---|---|---|---|
| GU7 | Waverley | 287 | very hard |
| GU20 | Surrey Heath | 287 | very hard |
| GU47 | Bracknell Forest | 287 | very hard |
| GU6 | Waverley | 225 | hard |
| GU19 | Surrey Heath | 225 | hard |
| GU27 | Waverley | 225 | hard |
| GU22 | Woking | 204 | hard |
| GU9 | Waverley | 204 | hard |
| GU1 | Guildford | 204 | hard |
| GU12 | Guildford | 154 | moderately hard |
| GU17* | Hart | 154 | moderately hard |
| GU10* | Waverley | 154 | moderately hard |
| GU46* | Hart | 154 | moderately hard |
| GU2 | Guildford | 154 | moderately hard |
| GU11* | Rushmoor | 154 | moderately hard |
| GU14* | Rushmoor | 154 | moderately hard |
| GU23 | Guildford | 154 | moderately hard |
| GU28* | Chichester | 154 | moderately hard |
| GU31* | Chichester | 154 | moderately hard |
| GU32* | East Hampshire | 154 | moderately hard |
| GU51* | Hart | 154 | moderately hard |
| GU30* | East Hampshire | 154 | moderately hard |
| GU34* | East Hampshire | 154 | moderately hard |
| GU35* | East Hampshire | 154 | moderately hard |
| GU29* | Chichester | 154 | moderately hard |
| GU33* | East Hampshire | 154 | moderately hard |
| GU52* | Hart | 154 | moderately hard |
| GU8 | Waverley | 141 | moderately hard |
| GU21 | Woking | 141 | moderately hard |
| GU3 | Guildford | 138 | moderately hard |
| GU24 | Surrey Heath | 138 | moderately hard |
| GU15 | Surrey Heath | 138 | moderately hard |
| GU18 | Surrey Heath | 88 | moderately soft |
| GU26 | East Hampshire | 88 | moderately soft |
| GU5 | Waverley | 88 | moderately soft |
| GU4 | Guildford | 75 | moderately soft |
| GU16 | Surrey Heath | 75 | moderately soft |
| GU25 | Runnymede | 75 | moderately soft |
You do not need a softener in Guildford.
At 154 mg/L the practical effects are minor. If you notice anything, it is usually chlorine rather than hardness: a shower filter or a filter jug deals with that.
Check your exact postcode
The area figure is a median. Your district can sit anywhere between 75 and 287 mg/L.
Questions about Guildford water
Is Guildford a hard water area?
No. The median hardness across GU postcode districts is 154 mg/L calcium carbonate, which is moderately hard. 24% of the 38 districts we hold readings for are hard or very hard (180 mg/L and above).
What is the water hardness in Guildford?
Between 75 and 287 mg/L depending on the district, with a median of 154. The hardest measured district is GU7 at 287 mg/L and the softest is GU25 at 75. Figures come from water company drinking-water tests, with postcode-area estimates for districts that have no reading of their own.
Do I need a water softener in Guildford?
Usually not. At a median of 154 mg/L limescale is a minor issue in Guildford. A filter jug or a shower filter covers the everyday effects. Only districts at 180 mg/L or above are worth a softener quote.
Hardness as mg/L calcium carbonate from water company drinking-water tests and postcode checkers. See the UK hardness map for every area.