Replacement cartridge · Fits every Duryn One
Carafe filtrante Duryn One
Everything the Clean cartridge does, plus an ion-exchange stage that pulls out the carbonate hardness behind limescale. For hard-water homes, kettles and coffee machines.
- Same filtration as Clean: PFAS, lead, chlorine, microplastics
- Reduces carbonate hardness, the cause of limescale
- Lower dissolved solids; cleaner tea, coffee and steam
- 200 litres or 3 months — may be shorter in very hard water.
30-day money-back guarantee
- Fits every Duryn One, including the first drop
- Clicks in. No screwing, no leaks
- Tested by IAPMO R&T to NSF/ANSI protocols
- Refill Plan: skip or cancel anytime
In the box: One sealed cartridge in a recyclable tube. No plastic wrap.
What's inside
Best for: Hard water: scale in the kettle, a film on your tea, spots on the glasses.
- 1
Stainless pre-screen
Catches sediment and rust before they reach the block.
- 2
GravityPlus™ carbon block
The same block as the Clean cartridge: PFAS, lead, chlorine, VOCs and microplastics out.
- 3
Ion-exchange stage
Weak-acid cation resin swaps out the calcium and magnesium carbonate that becomes limescale. No salt involved.
What it does to your water
Every claim here has a lab report behind it. The full list, with percentages, is on the lab results page.
Reduces
Changes
Softer. Tea and coffee brew cleaner, the kettle stays clear.
Which cartridge is right for you?
Same fit, same carbon block. The difference is what happens after the block.
| Clean | Alkaline | Softener | |
|---|---|---|---|
| Best for | Most municipal tap water | Flat or heavy-tasting water | Hard water and limescale |
| PFAS, lead, chlorine, microplastics | Reduced | Reduced | Reduced |
| Extra stage | None | Magnesium mineral stage | Ion-exchange stage |
| Limescale | Unchanged | Softer taste | Reduced |
| pH | Unchanged | Raised | May drop slightly |
| Minerals | Kept | Magnesium added | Calcium and magnesium reduced |
| Taste | Clean, neutral | Smooth, slightly sweet | Soft; better tea and coffee |
| Cartridge life | 3 months | 3 months | 3 months, less in very hard water |
Replacing takes two seconds
No screwing, no tools, no wet hands. The QR code on the tube opens this guide.
- 1
Lift and pull
Take off the walnut lid and lift the old cartridge straight out of the steel funnel.
- 2
Rinse
Hold the new cartridge under the cold tap for 30 seconds to wet the carbon block.
- 3
Click
Drop it into the funnel and press until you feel it seat. Fill, discard the first pitcher, then drink.
Specifications
- Fits
Duryn One, every edition
- Capacity
200 L (about 52 US gal) or 3 months
- Water
Municipally treated tap water, 4–30 °C
- Testing
Activated carbon certified to NSF/ANSI 42 and 372; tested to NSF/ANSI 53 and 401 at IAPMO R&T
- Made in
Assembled in India
Reviews
Questions
How do I know when to replace it?
Every 3 months or 200 litres, whichever comes first. We email a reminder from the day your cartridge ships. On the Refill Plan the next one arrives before you need it.
Can I switch between Clean, Alkaline and Softener?
Yes. All three have the same click-in fit, so you can change any time. On the Refill Plan, change the cartridge type in your account before the next delivery.
Does it fit the first-drop pitcher?
Yes. Every Duryn One uses the same cartridge mount.
Do I need to prime a new cartridge?
Rinse it under the cold tap for 30 seconds, click it in, and discard the first full pitcher. After that, drink.
Will it fit a Brita or another pitcher?
No. The click mount is Duryn's own design, and the cartridge only fits the Duryn One.
Will it remove all limescale?
It reduces carbonate hardness, which is what forms scale. In very hard water the ion-exchange stage fills up faster, so the cartridge may need changing before 3 months.