White fine filter refill for a 1,900 L per day RO unit, threaded end cap at the top

Grey C1 carbon refill with fine mesh for a 1,900 L per day RO unit

White C2 carbon refill for a 1,900 L per day RO unit, threaded end cap at the top

Reverse osmosis membrane in a white housing with a black label, for a 1,900 L per day osmosis unit

White fine filter refill made of polypropylene fleece for a 3,800 L per day reverse osmosis unit

White C1 carbon refill with a black label for a 3,800 L per day reverse osmosis unit

Reverse osmosis membrane in a white housing with a black label, for a 3,800 L per day osmosis unit

Replacement cartridges and membranes for ARKA myAqua 1900 or 3800 reverse osmosis unit

Name: Replacement cartridges and membranes for ARKA myAqua 1900 or 3800 reverse osmosis unit
Brand: ARKA
SKU: FFRMD
Availability: InStock

17,90 €

5,96 € × 3 with no fees Klarna.

These refills and membranes renew the large ARKA myAqua reverse osmosis units of 1,900 and 3,800 L per day. The refills slip into the housings already in place, and the membrane is chosen according to your model in the selector.

Ref. FFRMD·Cartridge for reverse osmosis unit

Pièce : Recharge filtre fin, 1900

Recharge filtre fin, 1900

Recharge charbon C1, 1900

Recharge charbon C2, 1900

Membrane 1900

Recharge filtre fin, 3800

Recharge charbon C1, 3800

Membrane 3800

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Delivery within 2 to 15 business days

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The summary

What it is: the fine filter and carbon refills, and the membranes for the 1,900 and 3,800 L per day reverse osmosis units.
The principle: a refill replaces only the inner cartridge, the housing stays on the unit.
When to change: the refills every 6 to 12 months, the membrane of the 1,900 after 12 to 24 months.
How it arrives: by parcel to your home, each part in its original packaging.

Internal cartridges and membranes for high-flow reverse osmosis units

A high-output reverse osmosis unit passes hundreds of litres of tap water through its filters every day, so its cartridges wear out at the pace of your production. The wear parts offered here fit the two large ARKA myAqua models, the 1,900 L per day one and the 3,800 L per day one: the fine filter refills, the carbon refills and the membranes. By changing them in good time, you get back the water quality and output of the first days, without replacing the unit or its housings.

🧱 Refills and housings

On these two reverse osmosis units, each pre-filtration stage consists of a housing fixed to the unit and an inner cartridge that slides into it. The refill is just this cartridge: you unscrew the housing, remove the old cartridge, put the new one in its place and screw it back. The housing, its seals and its fittings stay in place, which makes the job quicker and cheaper than replacing a complete filter. The refills for the 1,900 measure 24.5 cm long by 6.5 cm in diameter, and those for the 3,800 measure 29.3 cm by 6.7 cm, so the parts for one model do not fit the housings of the other.

💧 What each stage retains

The water passes through the stages in a precise order, and each one protects the next. The fine filter first stops suspended particles, such as rust and sand, using a polypropylene sheet with a fineness of 1 micron. The C1 carbon, a block of activated carbon, then retains chlorine, odours and discolouration of the water, which protects the membrane, since chlorine degrades its material. The membrane then separates the water from almost all of its dissolved salts, and the C2 carbon, made from coconut shell and placed after it, completes the removal of chlorine, pesticides and medication residues. Both reverse osmosis units have these four stages, but their parts are not the same size.

Fine filter

Its 1 micron fleece traps the rust and sand that would clog the carbon.

Carbon C1

Its activated carbon block removes chlorine, odours and discolouration from the water.

Carbon C2

Its coconut shell charcoal complements the C1 against pesticides and medication.

Membrane

Its 0.0001 micron pores retain up to 99% of salts, metals and bacteria.

A covered reservoir for remineralising RO water

An osmosis unit producing 1,900 L a day fills a container quickly, and the water it produces is best stored before use rather than sent straight into the tank. The 170 L hydroponic reservoir with lid holds this water away from dust and light. There you remineralise your reverse osmosis water to the dose you want, then draw it off for water changes and top-ups, always with the same composition.

Switch off the water before opening a housing

Turn off the water supply and unplug the reverse osmosis unit before unscrewing any housing, then let the pressure drop by opening the osmosed water outlet. A housing opened under pressure sprays its water out all at once and can damage its seal. When refitting, check that the seal is properly seated in its groove before screwing back on by hand.

🌿 RO water in aquaponics

A large reverse osmosis unit comes into its own when you are handling big volumes, such as an aquaponics greenhouse, several tanks or a tank that has to be filled before start-up. Starting with water stripped of its nitrates and salts means you know that the nitrates measured afterwards really come from your fish, and not from your mains supply. This water must, however, be remineralised before it goes into a living system, because it no longer contains the carbonates that stabilise the pH. The article on pH regulation in aquaponics explains this step in detail, and the carbonate hardness test confirms the result.

📆 Planning your water changes

The cartridges on the 1 900 should be changed after 6 to 12 months, and its membrane after 12 to 24 months of use, depending on the hardness of your water and the volume produced. On the 3 800, the fine filter cartridge should be changed after 6 months at the latest and the carbon cartridges after 6 to 12 months, while the membrane is replaced according to the load of your incoming water. The surest way to decide remains measuring the TDS of the water produced, which you compare with the value recorded with new parts: above 50 ppm, the water no longer has the purity of osmosed water, and a lasting rise points to a worn part. A pocket TDS tester is enough to track this value. Always change the pre-filters first, since a saturated carbon lets chlorine through to the membrane, then let the unit produce for 30 to 60 minutes to waste before keeping the water.

Technical specifications

RO unit producing 1,900 L per day

Fine filter refill: 1 µm, polypropylene24.5 cm long, 6.5 cm in diameter
C1 carbon refill: Activated carbon block
C2 carbon refill: Activated carbon pelletsCoconut shell charcoal
Membrane: 27.5 cm, 10 cm in diameterRetention of up to 99%, 12 to 24 months of use

RO unit producing 3,800 L per day

Fine filter refill: 1 µm, polypropylene29.3 cm long, 6.7 cm in diameter
C1 carbon refill: Activated carbon blockSame dimensions as the fine filter refill
Membrane: 33.5 cm long, 10.6 cm in diameterFlow rate up to 2.64 L per minute
Filter flow rate: Up to 3 L per minute

Conditions of use

Pressure: 1 to 4 bar or 1 to 4.5 barFor the 1,900, then for the 3,800
Refill interval: 6 to 12 monthsAt the latest 6 months for the 3800's fine filter

To budget for separately

Checking the water produced: A TDS readingBelow 50 ppm, the reverse osmosis water is of good quality
Storage: A covered reservoirTo remineralise the water before use

4 further specifications are available in the detailed view.

In the box

1 refill or 1 membrane, depending on the part you choose

Mesh sizes, dimensions, flow rates, pressures and intervals taken from the instructions and technical data sheets for the ARKA myAqua 1900 and 3800, on 08/10/2026 and 11/10/2026.

Parts for the 1,900 or the 3,800

The refills and membranes of the two large reverse osmosis units only fit their own model.

1,900 or 3,800 L per day? The flow rate printed on the label is enough to identify the right parts.

	Model	Production (L per day)	Carbon stages	Refill length	Membrane	Price
Recommended Replacement cartridges and membranes forYour choice	myAqua 1900	1900 L per day	C1 and C2	24.5 cm	27.5 cm long	109,90 €
Replacement cartridges and membranes forYour choice	myAqua 3800	3800 L per day	C1 and C2	29.3 cm	33.5 cm long	169,90 €

Replacement cartridges and membranes forRecommended

The RO unit

ModelmyAqua 1900

Production (L per day)1900 L per day

Carbon stagesC1 and C2

The dimensions

Refill length24.5 cm

Membrane27.5 cm long

Replacement cartridges and membranes for

The RO unit

ModelmyAqua 3800

Production (L per day)3800 L per day

Carbon stagesC1 and C2

The dimensions

Refill length29.3 cm

Membrane33.5 cm long

Outputs, filtration stages and dimensions taken on 11/10/2026 from the ARKA myAqua 1900 and 3800 technical data sheets.

Estimate your
delivery time

The parts are sent in a parcel, each in its original packaging, delivered to your home by Colissimo or Chronopost, your choice at checkout. The exact cost is calculated in your basket according to the total weight of your order.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

Which part matches my reverse osmosis unit?

Stage	1,900 L per day	3,800 L per day
Fine filter	Fine filter refill, 1900	Fine filter refill, 3800
Carbon	C1 and C2 refills, 1900	C1 carbon refill, 3800
Membrane	Membrane 1900	Membrane 3800

What is the difference between a refill and a complete filter?

How often should the parts be changed?

Why two stages of carbon?

How do you change a cartridge?

Can the membrane from the 1,900 be used on the 3,800?

How can I tell the membrane is weakening?

Should a new refill be rinsed?

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Offered depending on the cart amount, at checkout.

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Replacement cartridges and membranes for ARKA myAqua 1900 or 3800 reverse osmosis unit

The summary