Last updated: 30 March 2026

This is an opinion piece. Views expressed are the author's own and do not constitute professional advice.

Cool Factor: 4/5

This Phox water filter review is based on six months of daily use in London, one of the hardest-water areas in the UK. Spoiler: the kettle has never looked better. Phox is a Glasgow-based company that makes the world's first refillable water filter cartridge, and after half a year of testing the Clean blend we're ready to give you the full, honest verdict on taste, cost, eco credentials and whether it's genuinely worth ditching Brita for good.

What is Phox Water?

Phox Water is a Scottish filtration brand founded in 2019 with a simple pitch: stop sending plastic filter cartridges to landfill. Instead of replacing an entire cartridge every month (the Brita model most of us grew up with), Phox uses a reusable cartridge that you top up with fresh filter granules every 45 days or 200 litres. The granules arrive through your letterbox in compostable packaging, and the cartridge itself stays put. Everything is designed and manufactured within a 30-mile radius of the company's Glasgow HQ.

There are currently two jug options. The V2 is a 2.2-litre glass jug that looks genuinely handsome on a kitchen counter, priced at around £40. The Wave is a 2.8-litre BPA-free plastic jug that costs roughly £25 to £35 depending on the bundle, and crucially fits inside most fridge doors. Both use the same refillable cartridge, so the choice is really about aesthetics versus practicality. Phox also sells a Maxtra-compatible refillable cartridge if you want to keep your existing Brita jug but switch to the refill system.

First impressions

Setup is straightforward but not instant. You place a carbon felt disc into the cartridge lid, pour in the granules, soak the assembled cartridge for about six minutes, then run two full reservoirs through before drinking. It takes around 15 minutes end to end, which is marginally more involved than dropping a Brita cartridge into a jug. After that first setup, though, subsequent refills are quicker because you skip the soaking step. Instructions are clear, and the Phox app sends a notification when it's time to swap the granules.

One thing worth noting: during our first fill, a small amount of water seemed to bypass the cartridge and trickle down the side. A quick reseat solved it immediately. A handful of Trustpilot reviewers mention the same thing, so it's worth double-checking the cartridge is properly locked in before your first pour.

The experience: six months in London

We tested the Clean filter blend, which is Phox's hard-water option. It targets chlorine, copper, lead and limescale. London tap water is notoriously hard, and our kettle used to fur up within a couple of weeks with a standard Brita. After six months with the Phox Clean filter, the inside of the kettle is still free of limescale. That alone would have sold us.

Taste-wise, the water comes out noticeably smoother and sweeter than unfiltered London tap water. It's the kind of difference you stop noticing after a week because it just becomes normal, but switching back to unfiltered water for a day (we forgot to refill on time once) made the contrast obvious again. Friends who've tried it blind alongside tap water have consistently picked the filtered glass as the better-tasting option.

There's also an Alkaline blend that adds magnesium and raises the pH, which may suit people in softer-water areas who want the mineral boost. We stuck with Clean because hard water was the problem we needed solved, and it delivered.

The subscription service deserves a mention. You pick your blend, set your frequency, and refill packs arrive before you run out. It's cancellable any time and removes the mental overhead of remembering to reorder. At around £14 for a three-month supply (two sachets), the ongoing cost is lower than the equivalent in Brita Maxtra cartridges.

Value for money

An independent cost breakdown puts Phox at roughly £0.035 per litre versus around £0.042 per litre for Brita Maxtra. That's a modest saving per glass, but over a year of daily use it adds up, and you're generating significantly less plastic waste in the process. Phox's refill sachets are compostable, and the cardboard packaging is made from recycled materials. Phox Water's official site has a full breakdown of what each filter removes and how the refill cycle works.

On Trustpilot, Phox currently holds a rating of 4.6 out of 5 from over 10,800 reviews. The most common praise centres on taste improvement, reduced limescale and the eco-friendly refill model. The occasional criticism relates to initial setup fiddliness or delivery hiccups, but the company appears responsive to complaints.

Phox is also stocked at John Lewis, Ocado and Amazon, so you have plenty of options when it comes to where you buy. For more detail on features, jug options and pricing, see our Phox detail page.

Phox water filter review: the verdict

After six months, the Phox Water filter has earned a permanent spot in our kitchen. It does exactly what it promises: cleaner, better-tasting water with less plastic waste and lower running costs than Brita. The refillable cartridge system is genuinely clever, the subscription removes any friction, and the results speak for themselves in a limescale-free kettle and water that's actually enjoyable to drink straight.

Overall, a solid 4/5 Stone cold. The Phox Water filter earned its score through genuine everyday performance: no limescale in hard London water, noticeably better taste, a smart refill system that slashes plastic waste, and running costs that undercut Brita. It didn't quite reach Ice cold because the initial setup is slightly fiddly compared to a drop-in cartridge, the jug capacity is modest (the glass V2 only holds 2.2 litres), and the product range is still fairly narrow. But for anyone who's tired of chucking plastic cartridges in the bin every month, this is a properly impressive alternative.

Phox water filter: frequently asked questions

Is the Phox water filter better than Brita?

In our experience, yes. The refillable cartridge produces less plastic waste, the per-litre running cost is lower (roughly £0.035 vs £0.042 for Brita Maxtra), and the Clean filter handled London's hard water more effectively than any Brita we've used. Phox also offers a Maxtra-compatible refillable cartridge, so you can test the system without buying a new jug.

How often do you need to change Phox filter granules?

Every 45 days or 200 litres, whichever comes first. The Phox app tracks usage and sends a reminder when it's time to swap. Refill sachets arrive through your letterbox if you're on the subscription.

Does Phox remove limescale?

The Clean filter blend is specifically designed for hard water and targets limescale buildup. After six months of use in London, our kettle showed no visible limescale at all.

Where is Phox Water made?

Everything is designed and manufactured in Glasgow, Scotland. Phox states that manufacturing, packaging, design and distribution all happen within a 30-mile radius of their headquarters.

Can I use Phox refills in my Brita jug?

Yes. Phox sells a refillable Maxtra-compatible cartridge that fits standard Brita jugs. This lets you switch to the refill granule system without replacing your existing jug.

How much does a Phox water filter cost?

The Wave plastic jug starts at around £25 to £35 with a three-month filter pack. The V2 glass jug is roughly £40. Ongoing refill packs cost about £14 for a three-month supply.

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