Most “best water filter” articles rank products based on marketing materials. We do it differently: we match filters to contaminants actually found in UK tap water, using government data from the Environment Agency and water company compliance reports.
UK tap water is safe to drink. It meets strict legal standards. But “legal” and “ideal” are different things — trace amounts of chlorine, lead from old pipes, PFAS, and nitrates from farming can all be present within legal limits. The right filter depends on what is in your water and what you want to remove. This page helps you work out which type you need, then links to our detailed buying guides for each category.
Our buying guides contain 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. Our recommendations are based on certifications and contaminant data, not sponsorship. Full disclosure
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What each filter type removes
Different filter technologies remove different things. This table shows what you can realistically expect from each type, based on independent certifications rather than manufacturer claims.
Filter type
Chlorine
Lead
PFAS
Fluoride
Bacteria
Hardness
Jug (carbon)
Jug (ion exchange)
Countertop
Under-sink
Reverse osmosis
Whole house
RemovesPartialNo effect
Choose your filter type
We have written a detailed buying guide for each filter category, with specific product recommendations tested against real UK water quality data.
The single most important thing when choosing a filter is independent certification. Marketing claims mean nothing without third-party verification. Here are the certifications that matter:
NSF/ANSI 42Reduces chlorine, taste, and odour. The baseline.