How Sandown compares
At 195 mg/L (13.7 °Clark), Sandown is 20% below the median of the 411 English towns on this map (243 mg/L). It ranks 255 of 411 for hardness (1 is the hardest).
Water hardness in Sandown
Sandown has moderately hard water: some limescale, but easy to keep on top of.
Data
| Value | 195 mg/L calcium carbonate 13.7 °Clark, 10.9 °dH |
|---|---|
| Band | moderately hard |
| Area | Isle of Wight |
| Population | 20,155 |
| Water company | Southern Water |
| Postcode checked | PO36 9FD (ZI503) |
| Checked | 21 Oct 2026 |
| From the source | “"waterZoneReference":"ZI503","totalHardness":78.0 (Cal mg/l),"supplySource":"Your water is pumped from underground sources in the chalk a"” |
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 Sandown?
The water company's figure for Sandown is 195 mg/L (13.7 °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
Ryde 9 km Newport 11 km Cowes 16 km Gosport 16 km Portsmouth 17 km Fareham 22 km Havant 26 km Waterlooville 27 km