You track your sleep, your training, your diet.Control your home's
water health.
Test your tap water. Get a score, a clear picture of how it affects your health goals, and a Care Plan to improve it.
Water is HealthMethodology by researchers at Imperial College London and University of Cambridge
“I spent £180 on a filter I completely trusted. WaterGraph showed it was doing nothing for the hardness behind my dry skin and then they gave me a real plan to fix it.”
“I track my sleep, nutrition and exercise with Oura and Zoe. Water was literally a missing input and a gap in my stack for living to 90!”
“My two are forever drinking from the tap and I’d never once thought about what’s in it. Now I’ve got a number and can see when it's not safe.”
Same city. Different water.
Your water is tested at the treatment works. Then it travels through Victorian mains, your building’s pipework, and maybe a roof tank before it reaches your glass.
The grid is monitored. Your tap is not.
What arrives at your tap can differ from the flat next door, and from one season to the next. You optimise everything you can measure. This is the input you’ve been taking on faith.
What happens and what to do next.
Take the test
A technician comes to your home, collects the sample, and then brings the sample to our lab.
We're in-and-out in 5 mins.
Get your score via our app
Our lab measures 12 parameters, including: E-Coli, lead, copper, iron, manganese, zinc, nitrate, fluoride, hardness and pH.
Within five days you get your Water Health Score, what we found for each parameter, why it’s there, and if it matters for your personal health goals.
What next: Your Care Plan
So what do you do with your results? Your Care Plan is the answer.
Every flagged parameter gets one specific action – a filter setting, a £30 part, a first-draw habit, a letter to your landlord – ranked by impact, effort and cost. All of our advice is independent, commission-free, and based on our own efficacy testing.
Be in the loop
When something changes – storm damage, a local incident, a supply shift – our alerts ensures that you're the first to know what changed, what it means, and what to do about it.
Insights also show where you stand: your water against your area, against other WaterGraph homes, and the impact from the weather in the next 48 hours.
Retest to maintain performance
Scores become less accurate because water shifts.
Your retest proves the fixes worked, updates your score, and ensures that your water retains a peak health status for you.
Water is Health.
Start measuring it.
We are our science.
Cambridge Lakehouse is a spinout from the University of Cambridge. WaterGraph’s methodology is designed and stress-tested by researchers at Imperial College London and the University of Cambridge – and published in full, so you never have to take our word for anything.
Dr Ralph St Clair Wade
Head of Research. Affiliated Lecturer, University of Cambridge.
Dr Tom Rowan
Professor of Subsurface Hydrology, Imperial College London. Water sensors and field instrumentation.
Prof Adrian Butler
Professor of Subsurface Hydrology, Imperial College London.
Independent, by design. We do not sell filters. We take no commissions. Nobody pays us to reach a conclusion. Your results are yours alone.
Own your water health
- 1 Water Test
- Water Health Score
- Care Plan
- Results Breakdown
- Everything in Home Water Test
- 2 Water Tests in 12 Months
- Compare Your Results Over Time
- Benchmark Against Your Area
- Local Alerts, Insights & Forecasts
- Water health certification for your home
Water health, taken seriously.
Questions, answered plainly.
Is London tap water safe to drink?
London’s mains water meets UK regulatory standards when it leaves the treatment works – but no statutory test covers the final stretch into your home, where Victorian mains, building pipework, tanks and fittings change what actually reaches your glass. That last stretch is what WaterGraph measures: a 12-parameter lab test at your tap, scored and explained.
What is a Water Health Score?
Your Water Health Score is WaterGraph’s 0–100 measure of the water at your kitchen tap, built from a 12-parameter laboratory panel and a published methodology developed with researchers at Imperial College London and the University of Cambridge. One number tells you where you stand; the parameter-by-parameter detail tells you why. Read the full methodology →
How does testing work?
A WaterGraph technician comes to your home, collects samples from your kitchen tap – in and out in five minutes – and brings them to our lab. Within five days, your Water Health Score, full results and Care Plan arrive in the WaterGraph app.
What do you test for?
We test 12 parameters, built for long-term health relevance: E. coli, lead, copper, zinc, iron, manganese, a wider heavy-metals screen, nitrate, fluoride, hardness, alkalinity and pH. Every threshold is published with our methodology – nothing is a black box.
What happens if my results show a problem?
Your Care Plan gives every flagged parameter one specific action and solution – a filter setting, a £30 part, a first-draw habit, a letter to your landlord – ranked by impact, effort and cost. We sell no filters and take no commissions, so the advice is only ever advice.
I already have a filter. Do I need this?
A filter changes some parameters and not others – and without a before-and-after measurement, you can’t know which. Testing shows what your filter is actually doing at your tap, what it’s missing, and whether it’s still doing it as the device ages.
How is this different from a cheap test strip?
Strips give you a colour to squint at; WaterGraph gives you laboratory measurements of 12 parameters, one score you can track over time, and a Care Plan for what to do next – with the methodology published in full. You’re not buying a reading, you’re starting a record.
Is this a subscription?
No. You pay once. The 12-Month Assurance simply lasts a year – two tests, alerts, insights, your Watermark. When it ends, renewing is your choice.
Why do I apply rather than just buy?
Capacity. For now, samples are taken by someone on our team, so London member numbers are limited for this month.
Is my data private?
Yes. Your results are yours under UK GDPR – we never sell personal data, and area insights only ever use anonymised, district-level statistics.
Where do you operate?
London. For elsewhere in the UK, take the quiz to join the early-access list when we expand out of London.