Tap Water in PO34
Your water is pumped from underground sources in the chalk at Sandown. — Southern Water
Tap water in Your water is pumped from underground sources in the chalk at Sandown., supplied by Southern Water, has the character of a chalk aquifer source, typical of southern and eastern England. It’s soft water, low in dissolved minerals, with a total hardness of 78 mg/L as CaCO₃.
Mineral composition
| mg/L | |||
|---|---|---|---|
| Calcium | ~72 | ||
| Magnesium | ~4 | ||
| Sodium | 29 | ||
| Sulfate | 32 | ||
| Chloride | 63 | ||
| Bicarbonate | ~168 | ||
| ~ Estimated from hardness and ion balance — not directly measured by the water company. | |||
Additional info
| Hardness | 78 as CaCO₃ |
| Alkalinity | 137.4 as CaCO₃ |
| pH | 7.29 |
| Conductivity | 553.4 µS/cm |
| Source | Southern Water |
| Data year | 2024 |
What this means
Kettle & appliances
At this level of hardness, limescale is essentially a non-issue. Kettles, boilers, and heating elements will stay clean without treatment.
Espresso
Soft water is forgiving on espresso machines (no scale risk) but can produce a thinner, more acidic shot. The low mineral content means less buffering, so bright and sour notes tend to dominate. That said, lighter roasts can shine here in ways they won’t in harder water.
Filter & pour-over
This is where soft water shows its range. A V60 or Chemex will produce a bright, clean, highly readable cup with clear origin character. Light and medium roasts tend to be at their most expressive. It can tip into sourness with very light roasts, but for most specialty filter coffee, this water is close to ideal.
Drinking & cooking
This water tastes clean and neutral. It lathers easily, rinses cleanly, and won’t leave mineral deposits on glassware or cookware.
Bicarbonate
Significant buffering that pushes mash pH high enough to require acid additions for most beer styles other than stouts, and produces espresso that is notably flat and heavy, with muted acidity and a tendency toward a uniform, opaque flavour profile.
Get the best from your water
PO34 tap water works well for espresso and baking with little or no adjustment. Brewing is within reach with salt additions. It has too much mineral content for aquarium use, tea, and horticulture; a bottled water blend is the better route for those.
Nearby areas
Data sourced from Southern Water (2024). Looking for a specific address? Look up your full postcode for the most accurate result.