How Crawley compares
At 175 mg/L (12.3 °Clark), Crawley is 28% below the median of the 411 English towns on this map (243 mg/L). It ranks 279 of 411 for hardness (1 is the hardest).
Water hardness in Crawley
Crawley has moderately hard water: some limescale, but easy to keep on top of.
Data
| Value | 175 mg/L calcium carbonate 12.3 °Clark, 9.8 °dH |
|---|---|
| Band | moderately hard |
| Area | West Sussex |
| Population | 124,008 |
| Water company | Southern Water |
| Postcode checked | RH10 1JB (ZS516) |
| Checked | 21 Oct 2026 |
| From the source | “"waterZoneReference":"ZS516","totalHardness":70.0 (Cal mg/l),"supplySource":"Your water is pumped from Weir Wood reservoir and from the W"” |
What it means for your home
Moderately hard water leaves some scale, but slowly. The kettle and shower head need descaling now and then, and that is usually all.
The right detergent dose and a correctly set dishwasher are enough for most homes. A softener is rarely needed.
How often to descale
As a rule of thumb for moderately hard water, kettles and shower heads need descaling every six to eight weeks. Descale whenever you see scale building up.
Common questions
Is hard water bad for you?
No. Hard water carries calcium and magnesium, minerals the body uses. Whether tap water is safe depends on germs and pollutants, which water companies test for, not on hardness.
Do I need a water softener in Crawley?
The water company's figure for Crawley is 175 mg/L (12.3 °Clark), which is moderately hard water. Usually not straight away. Set the dishwasher, dose detergent for your band and descale regularly. Get quotes for a softener only if scale is clearly damaging your boiler or appliances.
How do I find the value for my address?
Use your water company's postcode checker. Hardness can differ between districts, so check your own postcode, or test with strips or a drop test.
Nearby towns
Horsham 12 km Redhill 14 km Leatherhead 23 km Coulsdon 23 km Banstead 23 km Epsom 25 km Purley 25 km Sutton 26 km