Best Water Testing Kit UK 2026
Test before you filter
Before you spend £50 to £500 on a water filter, spend £13 finding out what is actually in your water. We see people buy reverse osmosis systems when a £25 jug would have been enough — and others buy BRITA jugs when they have PFAS that only RO removes.
Our postcode tool uses data from 2,800 UK postcodes and 1.6 million readings to show you what your water company reports. But your specific home could be different — especially if you have old lead pipes or live at the end of a long supply line. A testing kit tells you what is coming out of your tap.
This guide contains affiliate links. If you buy through these links, we earn a small commission at no extra cost to you. This funds our independent water quality research. Full disclosure
Quick picks
Best quick screen
SimplexHealth 17-in-1 Water Test Kit
17 parameters in 2 minutes, cheapest option at £13
Best for ongoing monitoring
SJ WAVE 16-in-1 Premium Water Test
150 strips included, enough for monthly testing all year
Best for real answers
Tap Score Essential City Water Test
ISO 17025 accredited lab, 50+ parameters including PFAS
Start here: check your postcode for free
Before spending anything on a testing kit, try our free postcode tool. We pull data from the Environment Agency and water company compliance reports covering 2,800 UK postcode districts and 1.6 million individual readings. It will tell you what your water company reports for your area — including hardness, chlorine, lead, PFAS, and more.
A testing kit becomes valuable when you want to verify what is coming out of your specific tap, especially if you have older plumbing.
Free water quality check
Enter your postcode. We will show you what your water company reports for your area — no testing kit needed.
Try your postcode — e.g. SW1A, M1, B1
Dip strips vs lab tests: what is the difference?
Dip strips (£13–£15)
You dip a paper strip into your tap water, wait 60 seconds, and compare the colour changes to a chart. Quick, cheap, and good enough for a rough screening. They test for hardness, pH, chlorine, lead, iron, copper, nitrate, and more. The limitation: colour matching is subjective (especially in poor lighting), and they cannot detect PFAS, microplastics, or pharmaceutical residues. Think of them as a screening tool, not a definitive answer.
Lab tests (£80+)
You collect a water sample, post it to an accredited laboratory, and receive a detailed report with precise measurements for 50+ parameters — including PFAS, heavy metals, bacteria, and volatile organic compounds. The Tap Score Essential test uses an ISO 17025 accredited lab, which is the same standard used by professional water testing services. Results take 5–7 business days. If you need real numbers to make a filter purchasing decision, this is the only option that gives you them.
What to look for in a water testing kit
Number of parameters tested
More is generally better, but only if the extra parameters are relevant. For UK mains water, you want at minimum: hardness, pH, chlorine, lead, and nitrate. If PFAS are a concern (check your postcode first), only a lab test will detect them.
Accuracy and accreditation
Dip strips give you a range (e.g., “lead: 0–15 ppb”), not a precise number. That is fine for screening but not enough to make a confident filter decision. Lab tests from ISO 17025 accredited labs give you exact measurements with uncertainty ranges — the same standard that regulatory bodies use.
Number of strips included
If you plan to test regularly (monthly or quarterly), you want a kit with multiple strips. The SJ WAVE includes 150 strips — enough for over two years of monthly testing. Single-use lab kits like the Tap Score are one-time tests.
The three best water testing options for UK homes
Testing Kit
SimplexHealth 17-in-1 Water Test Kit
Best quick screen
£13
- Tests 17 parameters including lead, pH, and hardness
- Results in 2 minutes with colour-match strips
- Cheapest way to get a quick snapshot of your water
Testing Kit
SJ WAVE 16-in-1 Premium Water Test
Best for ongoing monitoring
£15
- 150 strips included — enough for regular monthly testing
- Tests bacteria, lead, iron, copper, and more
- Clear colour chart printed on the bottle label
Testing Kit
Tap Score Essential City Water Test
Best for real answers
£80
- ISO 17025 accredited lab — results you can trust
- Tests 50+ parameters including PFAS and heavy metals
- Online dashboard with personalised health recommendations
SimplexHealth 17-in-1 \u2014 Best quick screen
SimplexHealth 17-in-1 Water Test Kit
The cheapest and fastest way to get a snapshot of your water.
At £13, the SimplexHealth 17-in-1 is the obvious starting point. You get results for 17 parameters in about 2 minutes: hardness, pH, chlorine, lead, iron, copper, nitrate, nitrite, fluoride, and more. The colour-match system is straightforward in good lighting. It will not give you precise numbers — you are matching colours to a printed chart, which is inherently subjective. But it is accurate enough to flag obvious problems. If the strip shows elevated lead or high hardness, you know to investigate further with a lab test. If everything looks clean, you have peace of mind for £13.
Pros
- Tests 17 parameters including lead, hardness, pH, and chlorine
- Results in 2 minutes — the fastest option here
- Just £13 — the cheapest way to screen your water
- No lab, no postage, no waiting for results
Cons
- –Colour matching is subjective — poor lighting makes it worse
- –Cannot detect PFAS, microplastics, or pharmaceutical residues
- –Only provides ranges, not precise measurements
SJ WAVE 16-in-1 \u2014 Best for ongoing monitoring
SJ WAVE 16-in-1 Premium Water Test
150 strips in the box — enough for monthly testing for two years.
The SJ WAVE 16-in-1 tests one fewer parameter than the SimplexHealth, but the real selling point is quantity: 150 strips in the box, compared to the typical 10–15 you get from competitors. At £15 total, that works out to 10p per test. This makes it practical for monthly or even weekly monitoring. The colour chart is printed directly on the bottle label, which is convenient. One unique feature: it includes a bacteria test strip, though this requires a 48-hour incubation period and is the least reliable of the tests. For everything else — hardness, pH, chlorine, lead, iron — the results are comparable to the SimplexHealth.
Pros
- 150 strips included — 10p per test for regular monitoring
- 16 parameters including bacteria (48-hour incubation)
- Colour chart printed on the bottle for easy reference
- Practical for monthly or quarterly ongoing testing
Cons
- –Bacteria test requires 48-hour incubation — not instant
- –Same colour-matching limitations as all dip strips
- –Cannot detect PFAS or pharmaceutical residues
Tap Score Essential \u2014 Best for real answers
Tap Score Essential City Water Test
The only option that gives you precise numbers from an accredited lab.
The Tap Score Essential City Water Test is in a different league. You collect a sample, post it to an ISO 17025 accredited laboratory, and receive a detailed online report with precise measurements for 50+ parameters — including PFAS, all major heavy metals, bacteria, volatile organic compounds, and more. The online dashboard is excellent: it colour-codes each result against WHO and EPA guidelines and gives personalised health recommendations. At £80 it costs significantly more than dip strips, and results take 5–7 business days. But if you are trying to decide whether to invest £300–£500 in a reverse osmosis system, spending £80 to get definitive data first is the smart move. This is the test that tells you what filter you actually need.
Pros
- ISO 17025 accredited lab — the gold standard for water testing
- 50+ parameters including PFAS and heavy metals
- Online dashboard with personalised health recommendations
- Precise measurements, not subjective colour matching
Cons
- –£80 — significantly more expensive than dip strips
- –Results take 5–7 business days via post
- –One-time test — no strips for ongoing monitoring
Our verdict
Start with the free option: check your postcode on TapWater.uk to see what your water company reports. If you want to verify what is coming out of your specific tap, grab the SimplexHealth 17-in-1for £13 as a quick screen.
If your postcode flags PFAS, heavy metals, or elevated nitrate — or if you are considering a £300+ filter purchase — invest in the Tap Score Essential lab test at £80. Precise numbers from an accredited lab will tell you exactly which filter you need (and whether you need one at all).
For ongoing monitoring after you have installed a filter, the SJ WAVE 16-in-1at £15 for 150 strips is unbeatable value.
Frequently asked questions
Dip strip vs lab test — which should I use?
Dip strips (£13–£15) give you a quick snapshot in 2 minutes. They are good for a rough idea of hardness, pH, chlorine, and some metals. But the colour-matching is subjective and they cannot detect PFAS or microplastics. Lab tests (£80+) give you precise numbers for 50+ parameters including PFAS and heavy metals, analysed by an accredited laboratory. Use a dip strip first as a screening tool. If anything looks concerning, follow up with a lab test for confirmation before spending money on a filter.
What should I test my water for?
At minimum: hardness (affects appliances and skin), pH (affects pipe corrosion), lead (common in older homes with lead pipes), chlorine (always present in UK mains water), and nitrate (elevated in agricultural areas). If you are concerned about specific contaminants like PFAS or heavy metals, you need a lab test — dip strips cannot detect PFAS. Alternatively, enter your postcode on TapWater.uk for free data on what your water company reports for your area.
How do I take a proper water sample?
For dip strips: run the cold tap for 30 seconds to flush standing water from the pipes, then dip the strip directly into the flowing water. For lab tests: follow the kit instructions exactly — most require you to run the tap for 2 minutes, fill the provided bottles to the marked line without touching the inside, seal them immediately, and post within 24 hours. Temperature matters: keep the sample cool (not frozen) during transit. Morning samples before anyone uses water give the most revealing results for lead and bacteria.
How often should I test my water?
For peace of mind, once a year with dip strips is sensible — especially if you have older plumbing. Test again after any plumbing work, if you notice a change in taste, colour, or smell, or if your area has had a water quality incident. Lab tests are typically a one-time investment to establish a baseline. If you live in an area our postcode tool flags for any contaminant, annual testing is worth the cost.