A WaterGraph technician testing tap water in a family kitchen

Watermark your home

Independent water certification - developed with scientists at the University of Cambridge and Imperial College London. £29 for two tests, six months apart.

Book Your Water Test

Pay only when you receive your results.

How it works
What customers say

Real homes. Real verdicts.

★★★★★
“My filter wasn't doing its job. I'd been paying for it for two years.”
Sophie, New Forest
★★★★★
“He tested in our kitchen while the kids watched. Walked us through every reading.”
Doone, New Forest
★★★★★
“A real answer, with what to do about it. Not a strip kit and a shrug.”
Shaun, near Southampton
Developed with
Imperial College LondonUniversity of Cambridge
How it works

Twenty minutes. Three steps.

01
A WaterGraph engineer testing tap water in a customer's kitchen
The visit

A WaterGraph engineer comes to your home, often co-founder Hugh himself. Twenty minutes. Tests your kitchen tap for nine specific parameters in front of you.

02
An Attention Watermark on a phone
Your Watermark

One of three verdicts: Clear, Attention, or Action Required. On your phone. Date-stamped. Renewable every six months.

03
A sample WaterGraph report on a phone, with parameter readings and ranked recommendations
Your report

Every reading explained. Ranked recommendations with the reasoning attached. From independent efficacy research, never commercial relationships.

Book Your Water Test

Pay only when you receive your results.

The science

Developed at Cambridge and Imperial.

WaterGraph is a Cambridge Lakehouse company, working with scientists at the University of Cambridge and Imperial College London. Our methodology is independent, peer-reviewable, and benchmarked against UK and WHO drinking-water standards.

We don't sell filters. We don't take affiliate revenue. The Watermark is the product. The recommendations are independent.

Watermark your home

£29 for two tests, six months apart.

Book Your Water Test

Pay only when you receive your results.

New Forest properties only.