Best water filters for hard water: buyers guide
- Lucinda Smalley
- Nov 20
- 5 min read
Updated: Nov 21
Better-tasting water? Easy yes. Knowing which filter to buy? Surprisingly hard.
There are so many water filters out there - everything from basic jugs to fancy taps and full under-sink systems. If it all feels a bit confusing, you’re definitely not alone. Here’s our easy guide to water filters for UK hard water, and how to choose the one that’s right for your home.
In this article:
Filtered water that tastes nicer and slows down the limescale build-up in your kettle? Yes please!
I used a Brita jug for years but ditched it when we moved and it didn’t fit in our new fridge (classic!). At the plumbing company I also run - we’re getting more and more people asking us to install under-sink filters and filtered taps lately. So naturally I went down the rabbit hole: what are the main types of drinking water filters, what they do, and how do you choose the right one.
Here's my lowdown.
Who water filters are best for
If you're fed up with funny tasting tap water and replacing your kettle every year or two, a filter might be just what you need.
Water filters help improve taste and reduce certain contaminants and minerals, but they don’t technically “soften” your water. So while your tea might taste better and your kettle could last longer, filters won’t fix limescale in your pipes, boiler or shower.
A water filter is worth considering if you:
Mainly want better tasting drinking water
Want to reduce limescale in your kettle and coffee machine
Don’t need a full-house softener
If that’s you — keep reading.
What a water filter actually does
Generally water filters use a simple two-step process:
Carbon granules - basically a super-porous sponge. Usually made from coconut shells, the carbon grabs onto chlorine and other bits that make water taste or smell odd.
A fine membrane - think of it like a tiny sieve. This catches things like rust flakes, sediment, microplastics and general murkiness from old pipes.
Between the two, they remove or reduce chlorine (that swimming-pool vibe), rust and sediment, some metals, taste and odour problems and limescale forming minerals
Do they completely remove limescale?
Not completely (unless it's reverse osmosis - more on those below). But they often catch enough of the calcium and magnesium to make a visible difference in kettles and mugs.
So while your pipes and shower won’t magically change, your cuppa will.
The main types of water filters
Jug filters
Jug filters are the “starter pack” of water filtering. You fill them from the tap, wait a minute or two, and pour. No installation, no fuss, and they genuinely improve taste.
They’re ideal if you want filtered water on a budget or you’re not ready to commit to a plumbing upgrade. The only catch is how often you need to refill them and how heavy they are when full.
Best for: A low-cost, low-commitment upgrade
Price: £15–£40
Pros:
✔️No installation
✔️Easy to use
✔️Chill nicely in the fridge
✔️Widely available
Cons:
❌Heavy when full
❌Need lots of refilling
❌Slower flow
❌Frequent filter changes (usually monthly)
Popular brands: Brita, Amazon basics, Phox
On-tap filters
These little devices screw onto your existing tap (as long as it’s compatible) and give you filtered water instantly. They’re great if you want to avoid refilling a jug every few hours.
Design-wise they do make your tap look bulky and aren’t going to win any awards in the looks department, but they’re practical and surprisingly effective for everyday use.
Best for: Quick, easy filtered water straight from the tap
Price: £25–£80
Pros:
✔️DIY installation
✔️Switch between filtered/unfiltered
✔️Lower price
Cons:
❌Not the sleekest option
❌Won’t fit every tap
❌Filter changes every few months
3-in-1 filtered taps
A 3-in-1 looks like a normal, modern kitchen tap - but secretly gives you hot, cold and filtered cold water all in one. Under the sink sits the filter cartridge, dealing with taste issues, chlorine and some scale-forming minerals. If you want a neat, long-term solution (and you’d prefer a premium look), this could be a good option.
Best for: A permanent, stylish filtered tap
Price: £150–£350+
Pros:
✔️Clean, modern design
✔️Three water options in one tap
✔️Great taste improvement
Cons:
❌May need a plumber to install
❌Higher upfront cost
❌Cartridge changes every 6–12 months
Popular brands: Brita
Under-sink filters
These live quietly under your sink and give you filtered water without the clutter. You can either
run them to a separate small drinking-water tap, or connect them directly to your main kitchen tap using an inline filter
Inline under-sink filters
These are the simple cartridge-style systems that sit in your cold water line. They improve taste, reduce chlorine and sediment, and usually only need changing once a year. Think of them as the “minimal effort, maximum improvement” option.
Best for: Everyday filtration without changing your kitchen setup
Pros:
✔️Medium cost
✔️Easy installation
✔️Keep healthy minerals in
✔️Once-a-year filter change
Cons:
❌You might need a plumber if you don’t have flexihoses
❌Flow can slow when the filter is nearly done
❌If you’re renting you may need to get landlords permission
Popular brands: Water2
Reverse osmosis systems
Reverse osmosis systems take filtration to a whole new level - they strip almost everything out of the water, including minerals. If you’re worried about fluoride, nitrates or microplastics, this is the most powerful option.
They usually come with multiple cartridges and a small storage tank, so they take more space and cost more to run.
Best for: Ultra-pure drinking water
Pros:
✔️Premium filtration
✔️Removes a huge range of contaminants
✔️Taste improvement is noticeable
Cons:
❌More expensive
❌Bulky
❌Slower
❌Creates some wastewater
❌Removes beneficial minerals too
❌Not worth investment if renting
Popular brands: Waterdrop
Popular picks (based on what we actually install)
Water2 inline under-sink filter: A budget-friendly, fuss-free inline filter. Ideal if you want noticeably better-tasting water without redoing your kitchen.
BRITA Mypure 3-in-1 tap: A more premium, polished filtered tap with strong taste improvement and a neat, modern finish.
Are water filters worth it in hard water areas?
If your main frustration is the taste of your tap water and the limescale layer in your kettle, then yes, totally. A filter won’t soften your whole house, but it’ll make day-to-day life noticeably nicer.
Pair with a shower filter and you'll find noticeable improvements for your hair, skin and shower screen too.
And which one am I going for? I think for medium investment and maximum ease I'm going to try the Water2 - will report back how I get on!
Author bio: Lucinda is the founder of Hard Water Home, a UK-based blog helping households in hard water areas understand the challenges and solutions more easily — and make smarter choices for their health and home. Based in Poole, she also runs an award-winning plumbing company, giving her unique insight into how water quality affects our homes. Away from the desk, she’s happiest at the beach with her family and a good cup of coffee (minus the floaty bits!). More about us ➡
