Built with researchers at Imperial College
What's in your water?
Water companies test the grid, WaterGraph tests at your tap.
A lab test of your taps, a plain-English plan to fix what matters, and alerts through the year as we watch your water network.
Your water, on one page
Every test ends in a report built around your home: what we found at your tap, what it means, and what to do about it.
WaterGraph was created in partnership with researchers at Imperial College, London. We don’t sell water filters, and any recommendations we make are independent.
How it works
Order a test · Fill two bottles · Post them back
Your kit arrives in one working day with a returnable prepaid envelope. Simply fill the bottles and post it back.
Results in
48 hours
A plain English verdict and Care Plan, guiding you through what to fix and how to fix it.
WaterGuard
keeps watch
A second test in six months, and we send you alerts if your area has unsafe water network issues.
Pricing
Basic
- Results 48 hours after your sample reaches us
- A Care Plan: what to fix, and how
- Free post both ways
- Extra tests £49 each
WaterGuard
- Everything in Basic
- A second test posted in six months
- We watch your water network all year. We send you alerts if there’s an issue
- Extra tests £29 each
Premium
- Everything in WaterGuard
- A lab test for PFAS every year
- Extra tests £29 each
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Our customers
Know what your children are drinking
We check what matters most to them – lead from old pipes, nitrates, too much copper or iron – and tell you plainly if anything needs fixing, and how to fix it.
David, 38 years old, London
“I’d never thought about it until now… they’re always drinking from the kitchen tap, and before you guys I had no idea what was coming out of it… especially for the baby’s bottle.”
Every reading in plain English.
Exactly how to improve your water’s health, based on what you’re interested in, and what not to waste money on.
Water working for your body
Hardness, copper, iron, and pH all shape how water reacts with your skin, hair and gut.
Sarah, 29 years old, London
“Before I got the right filter, the only relief for my skin and hair was going to another country! Never knew that knowing what was in the water could help me make the right decision to get my confidence back.”
Results for what’s really coming out of it, not the area average, and your options to alleviate any issues.
Find out what makes sense for you, or if yours is working as intended.
Your missing health metric
You track your sleep, exercise, and diet. But the two litres you drink every day have never been tracked – no longer.
Kate, 44 years old, Hampshire
“I want to live a healthy and mobile life until I’m 95. I’ve started tracking my key metrics, but this was totally missing.”
One 0–100 number, built from 8 health indicators.
Test several taps in one order, and watch the numbers move as you fix things.
See how we score, line by line.
The science
What we test for
We test for the key indicators associated with water wellness and health:
What standard is our testing?
WaterGraph is a water screening service. We work hard to provide accurate results that help you make informed decisions about your health and wellness.
We regularly perform control tests to ensure that our accuracy remains high. Our processes have been built with researchers at Imperial College, London. We don’t certify water as safe for drinking, and we don’t offer a UKAS-accredited laboratory service.
How we recommend solutions and calculate the Water Health Score
The foundation of our company is to provide you with the truth. Your Care Plan is built on your readings and the evidence for what works, and nothing else decides what goes in it.
These recommendations are based on your test results, personal wellness goals, the proven efficacy of available solutions (free and paid), customer service ratings of paid solutions, cost, and effort.
Our team
Professor of Subsurface Hydrology at Imperial College London, specialising in subsurface water flow and contaminant transport – including the Chalk aquifers of Southern England. He works closely with the British Geological Survey and is Principal Investigator on the NERC-funded CAMELLIA project.
Nearly seven years advancing simulation tools and field instrumentation for water systems, combining low-cost sensor design with AI to tackle pollution and water security. His early-warning sensor research was highlighted by the American Geophysical Union. PhD in Fluid Mechanics at Durham, with postdoctoral research at Durham and Imperial.
Leads on research and operations at WaterGraph’s parent, Cambridge Lakehouse. Formerly Managing Partner of CambridgeCultura, a Cambridge research and insights spinout accredited by the Crown Commercial Service, and a Cambridge-funded visiting specialist at UNESCO. He took the top result in his year at St John’s College, Cambridge, where he held two doctoral scholarships. He is an Affiliated Lecturer at the University of Cambridge.
WaterGraph is a product by Cambridge Lakehouse
What's in your water?
FAQs
How accurate is this, and what happens if you find a problem?
WaterGraph is a water screening service. We work hard to provide accurate results that help you make informed decisions about your health and wellness, and we regularly run control tests to keep our accuracy high. Our processes were built with researchers at Imperial College, London. We don’t certify water as safe for drinking, and we don’t offer a UKAS-accredited laboratory service. Where a reading points to a possible compliance issue, we tell you plainly and we always recommend an accredited lab test to confirm it.
How does testing work?
Order your kit and it arrives in one working day. Fill two bottles from your tap (about five minutes), post them back in the prepaid envelope, and your Water Health Score and Care Plan are ready 48 hours after your sample arrives at our lab.
What do you test for?
8 parameters chosen for water wellness and health: lead, nitrate, copper, iron, fluoride, pH, alkalinity and hardness.
What’s included?
The home test kit with postage both ways, analysis of 8 parameters, your Water Health Score, a personal Care Plan, local water alerts, and support from our team whenever you need it.
Can I test more than one tap?
Yes, and it’s one of the most useful things you can do. Each tap needs its own kit: choose 1, 2 or 3 taps on Basic or WaterGuard and everything arrives in one order. Compare your kitchen against your bathroom, or the same tap with and without your filter.
What is WaterGuard?
A year of cover for your home’s water: a test now, a second posted to you in six months, and monitoring in between. We watch your home’s water network all year, including other WaterGraph tests near you, and you’re the first to know if there’s an issue.
What happens at six months?
We post your second kit automatically to the address on file. Nothing to remember.
What does monitoring mean?
We watch the readings around your home, from your own tests, other WaterGraph tests nearby, and the water network. If something changes that could affect your home, we email you.
Does WaterGuard renew?
Yes, yearly, at the same price, and you can cancel any time from your report or by replying to any email from us.
I bought a Basic test. Can I add WaterGuard later?
Yes. For 30 days after your results, your report offers WaterGuard for the difference, £10, and your first test counts as the first of the two.
How long do my results take?
48 hours after your sample arrives at our lab, typically three to four days door to door.
How do I collect my water sample?
Fill the two bottles from your tap following the instructions in the box. It takes about five minutes.
What if I already have a filter?
Then you’re our favourite kind of customer. The test tells you whether it’s actually working. Many customers test filtered and unfiltered water side by side, so pick two taps and label one filtered.
Will my report tell me how to fix any issues?
Yes. Your Care Plan says what each issue is, exactly how to fix it, and what not to waste money on.
Are your recommendations independent?
Yes. Every recommendation is chosen on your readings, your goals and the evidence for what works. No filter company or retailer has any say in your Care Plan, and no product is ever recommended because of a commercial relationship. If we ever earn anything from a link, we’ll say so on the page.
Do you test for PFAS, bisphenols, microplastics, hormones, or forever chemicals?
Not in the current 8-parameter panel. We focus on the indicators with the strongest evidence for UK tap water. Expanded panels are on our roadmap, and customers hear first.
What is my Water Health Score used for?
It turns 8 readings into one 0–100 number you can track, compare, and improve. It’s the headline for your home’s water, and the baseline for measuring any fix you make.
What is my Care Plan?
A plain-English action list built from your results and your goals: what’s fine, what needs attention, and the exact next step for each, free actions first.
What if I’m a renter?
Most fixes are tap-level, such as jugs, fittings and filters, with no landlord required. And if something bigger turns up, your report is solid ground for that conversation.
Do you serve the whole of the UK?
Yes, everything happens by post, UK-wide.