The Osmio EZFITPRO-400 is a different animal to the reverse-osmosis systems elsewhere on this site — and that’s exactly why it’s worth knowing about. It’s a UK-made, under-sink ceramic-and-carbon filter that costs a fraction of an RO system, uses no electricity and wastes no water. The trade-off: it’s not reverse osmosis, so it won’t purify as completely. Here’s the honest picture.
Who is this for?
The EZFITPRO-400 suits a budget-conscious UK household that wants cleaner, better-tasting water — including fluoride and chlorine reduction — without the cost, power and water-waste of reverse osmosis. It plumbs neatly under the sink to a separate tap, with no socket and nothing sent to drain. If you want genuinely comprehensive purification (TDS, full PFAS reduction), an RO system is the better choice — but it costs three times as much.
Key specs
| Osmio EZFITPRO-400 | |
|---|---|
| Type | Under-sink ceramic + carbon (not RO) |
| Stage 1 | Coldstream 0.2µm ceramic (85% fluoride) |
| Stage 2 | GAC phosphate & de-alk (limescale/metals) |
| Power / waste water | None / none |
| Filter life | 3–6 months (hardness dependent) |
| Fitting | 15mm push-fit, 3 bar pressure |
| UK price | £143.20 |
What it removes
The EZFITPRO-400 uses a Coldstream 0.2-micron ceramic cartridge (reducing ~85% of fluoride, plus chlorine, heavy metals, bacteria and cysts) followed by a GAC phosphate and de-alkalisation stage. Together they reduce fluoride, chlorine, heavy metals, bacteria, viruses, pharmaceuticals and sediment.
The honest caveat: because it’s not reverse osmosis, it doesn’t reduce TDS (total dissolved solids) the way RO does, and its limescale handling is chemical scale-prevention (de-alk dosing), not mineral removal. So it improves water quality considerably, but it isn’t the near-complete purification an RO membrane provides. See reverse osmosis vs carbon for the full distinction.
UK hard-water performance
In hard-water areas, the de-alk stage helps reduce scale formation rather than removing the hardness minerals themselves — so you’ll see less scale, but not the dramatic TDS drop an RO system delivers. Filter life is explicitly shorter in harder water (the rating drops from ~1080 litres at 150 ppm to ~540 litres at 300 ppm), so London-area users should budget for more frequent changes.
Installation
A straightforward 15mm push-fit under-sink job to a separate filtered tap, needing about 3 bar of incoming pressure. No power, no drain connection — simpler than an RO install. Confident DIYers will manage; otherwise a plumber will fit it quickly.
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With cartridges around £30–£35 each (the ceramic roughly yearly, the GAC de-alk every 3–6 months), budget roughly £80/year — still noticeably cheaper to run than RO, partly because there’s no membrane and no remineralisation consumable. In hard water, costs rise with more frequent cartridge changes.
How it compares
| Osmio EZFITPRO-400 | Waterdrop G3P600 (RO) | |
|---|---|---|
| UK price | £143.20 | £399.99 |
| Technology | Ceramic + carbon | Reverse osmosis |
| Removes TDS | No | Yes |
| Power / waste | None / none | Mains socket / some waste |
| Annual filters | ~£80 | ~£148 |
| Best for | Budget, soft-moderate water | Full purification, hard water |
Verdict
The Osmio EZFITPRO-400 earns 4/5 as a smart budget choice — a UK-made, low-cost, low-faff under-sink filter that genuinely improves water (including fluoride and chlorine) without electricity or waste water. We dock a point only because it isn’t reverse osmosis: in hard-water areas, or if you want the most complete purification including TDS and full PFAS reduction, the Waterdrop G3P600 is worth the extra. Buy the Osmio if budget, simplicity and no waste water matter most, especially in soft-to-moderate water areas. Step up to RO if you’re in a hard-water area or want maximum purification.
Frequently asked questions
Is the Osmio EZFITPRO-400 reverse osmosis?
No. It's an under-sink ceramic-and-carbon filter, not a reverse osmosis system. It reduces fluoride, chlorine, heavy metals and bacteria, but doesn't reduce TDS (dissolved solids) the way RO does. It's a cheaper, simpler alternative with no power or waste water.
Does the Osmio EZFITPRO-400 remove fluoride?
Yes — its Coldstream ceramic cartridge reduces around 85% of fluoride, along with chlorine, heavy metals, bacteria and cysts. It's one of the more affordable UK filters to offer meaningful fluoride reduction.
Does the Osmio EZFITPRO-400 waste water or need electricity?
Neither. Unlike tankless reverse osmosis systems, it runs purely on mains pressure with no electricity and sends nothing to drain — a genuine advantage on running costs and simplicity.
Is the Osmio EZFITPRO-400 good for hard water?
Partly. Its de-alkalisation stage reduces scale formation rather than removing hardness minerals, so you'll see less scale but not the big TDS drop reverse osmosis gives. Filter life is also shorter in hard water, so RO is the stronger hard-water choice.