Compact reverse osmosis unit ARKA myAQUA 190, 380 or 400

Regular price 49,90 €
Regular price Sale price 49,90 €

This reverse osmosis unit produces 190, 380 or 400 litres per day depending on the version, to prepare water for an aquarium or a circuit. The first two versions work on mains pressure alone, and the third discharges only 1 to 1.5 L of water per litre produced and displays the water quality.

Ref. 146.0009.01·Reverse osmosis unit
Flow rate : 190 l/day
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The summary

  • What you receive: the unit, its cartridges, its membrane, its tap fitting and its brackets.
  • How to choose: by the waste water and by whether a socket is available, not by flow rate.
  • What to plan for: a cold water tap and a container placed on the floor under the outlet.
  • How much effort day to day: changing the pre-filter and the carbon every 3 to 6 months on the 190 and 380 versions.

Three versions of top-up reverse osmosis unit, two of them without any power socket at all

The ARKA myAQUA reverse osmosis unit, available in 190, 380 and 400 versions, produces 190, 380 or 400 litres per day and removes 98 to 99% of dissolved salts to prepare water for an aquarium or a circuit. The 190 and 380 versions work without a power socket. The 400, powered by 48 W, discharges only 1 to 1.5 litres per litre produced, compared with 3 to 4 litres.

A top-up reverse osmosis unit screws onto a tap and gives you water stripped of 98 to 99% of its dissolved salts. The two smallest versions need no power socket: your mains pressure is enough to push the water against the membrane. You can store them in a cupboard between uses.

♻️ The water you throw away

The 190 and 380 versions

They discard 3 to 4 litres for every litre kept, since only mains pressure pushes the water against the membrane.

The 400 version

Its waste water falls to 1 to 1.5 litres for every litre kept, thanks to its 48 W power supply.

This volume of waste water sets these three units apart more than their daily output does. Between the 190 and the 380, you are buying speed: the latter produces twice as fast, in the same format and with the same yield. Between these two and the 400, you are changing to a different kind of unit: it plugs in, it sits on a stand, it displays the quality of the water it produces, and it wastes three times less. On 50 litres produced per week, the difference amounts to 75 to 150 litres of mains water.

🚰 What you need at the inlet

The fitting supplied screws onto a cold water tap, in 3/4 to 1/4 inch. A 3 metre pipe comes with the two smaller versions and a 5 metre one with the 400 version, and two wall brackets let you secure the whole unit rather than leaving it lying in the sink. The first two versions measure 35 x 19 x 10 cm and fit in an under-sink cupboard. The 400 version, at 35.5 x 22 x 44 cm, stands on its metal support, operates between 1 and 4 bar and accepts water from 5 to 45 °C. Above all, plan where the waste water goes: it must reach a drain, and the position of that drain determines where you install the unit.

Remineralising reverse osmosis water before it goes into the tank

The water this unit produces is practically free of minerals. It must be remineralised, or blended with tap water, before entering a stocked tank. Poured in on its own and in quantity, it shifts all your parameters at once. This precaution applies in an aquarium, in a pond and in aquaponics.

Check the membrane with a pocket tester

The pH, EC and TDS pocket tester from the same brand measures the conductivity of the water produced by the 190 and 380 versions, which have no display. Note the reading on the day of commissioning, then compare it from time to time: rising conductivity signals a cartridge or membrane that needs changing, before the water in your tanks is affected. You can also use it to check the conductivity obtained after remineralisation.

🧮 How long a container lasts

The 190 produces around 8 litres per hour and fills a 20-litre container in 2 h 30, the 380 in about 1 h 15. During that time, 60 to 80 litres go to waste. The 400 version, at 0.3 litres per minute, fills the same container in a little over an hour and discards only 20 to 30 litres. In aquaponics, this rate determines how it can be used: making up each day for the evaporation of a small circuit is within the 190's reach, whereas filling several hundred litres means producing water several days in advance. The article on pond evaporation in summer puts figures on the volumes involved.

🔧 Cartridges and membrane

On the 190 and the 380, the fine pre-filter is changed after 3 months or 11,000 litres produced and the activated carbon after 6 months or 5,500 litres, whichever limit is reached first, then the membrane after 24 months. On the 400 version, the cartridges are replaced every 6 to 12 months at the latest, and the built-in display tells you when the membrane is performing less well. The parts for all three versions are gathered on the ARKA myAQUA cartridges and membranes page. The reverse osmosis unit's carbon protects the membrane from chlorine in the mains water, and it does not replace the activated carbon in your tank's filter, which treats water that is already in circulation.

Technical specifications

Production and quality

Available versions
190, 380 and 400 L per dayThree different membranes for the same purpose.
Salt retention
98 to 99%Metals, nitrates and bacteria are also removed.
Discharged water, versions 190 and 380
3 to 4 L for 1 LOnly the mains pressure pushes the water against the membrane.
Waste water, 400 version
1 to 1.5 L for 1 LFor regular use, thanks to a 48 W power supply.

Installation

Inlet fitting
3/4 to 1/4 inchScrews onto a cold water tap, adapter supplied.
Dimensions, 190 and 380 versions
35 x 19 x 10 cmCompact enough to fit in a cupboard under the sink.
Power supply, 400 version
48 W, standby 1 to 2 WThe 190 and 380 versions do not need a power socket.
Safety cut-off, version 400
Under 0.8 barPressure that is too low stops the unit instead of slowing it down.

Maintenance

Cartridges, 190 and 380 versions
Pre-filter 3 months, carbon 6 monthsOr 11,000 and 5,500 litres produced; membrane after 24 months.
Cartridges, 400 version
Every 6 to 12 monthsThe built-in display monitors the quality of the water produced.

To budget for separately

Collection container
A food-grade containerPlaced on the floor, so you can fill without holding the pipe.
Remineralisation
Enough to raise conductivityOsmosis water should never be poured straight into a stocked tank.

4 further specifications are available in the detailed view.

In the box

  • 1 membrane and its membrane housing
  • 1 fine pre-filter cartridge
  • 1 activated carbon cartridge
  • 1 cartridge housing wrench
  • 1 tap fitting, 3/4 to 1/4 inch
  • 1 3 m pipe, 2 wall brackets and 4 clips

Manufacturer values recorded on 20/09/2026 from the product pages of the three versions, supplemented on 11/10/2026 from the ARKA myAQUA 400 page. The box contents described are those of the 190 and 380 versions.

Which reverse osmosis unit for your needs?

Three appliances that produce the same water, but do not discard the same amount of it.

The waste water and the power socket These units differ above all in the water sent down the drain and in the need for a socket nearby.

Maximum output (L/day)Output of the entry-level model (L/day)Salt rejection, at best (%)Water discarded per litre producedWorks without a power socketAutomatic production cut-offBuilt-in water quality monitoringPrice
Recommended
Compact reverse osmosis unit ARKA myAQUAYour choice		400 L/day190 L/day99 %3 to 4 L, 1 to 1.5 L on the 400 versionYesOn the 400 versionOn the 400 version49,90 €
Dupla RO 200 reverse osmosis unit supplied assembled, no electricity neededYour choice200 L/day200 L/day98 %3 to 4 LYesNoNo79,90 €
ARKA myAQUA 1900 or 3800 high-capacityYour choice3800 L/day1900 L/day99 %1 to 1.5 LNoYesNo309,90 €
Compact reverse osmosis unit ARKA myAQUARecommended
Production
Maximum output (L/day)400 L/day
Output of the entry-level model (L/day)190 L/day
Water produced
Salt rejection, at best (%)99 %
Water discarded per litre produced3 to 4 L, 1 to 1.5 L on the 400 version
Installation
Works without a power socketYes
Automatic production cut-offOn the 400 version
Built-in water quality monitoringOn the 400 version
Dupla RO 200 reverse osmosis unit supplied assembled, no electricity needed
Production
Maximum output (L/day)200 L/day
Output of the entry-level model (L/day)200 L/day
Water produced
Salt rejection, at best (%)98 %
Water discarded per litre produced3 to 4 L
Installation
Works without a power socketYes
Automatic production cut-offNo
Built-in water quality monitoringNo
ARKA myAQUA 1900 or 3800 high-capacity
Production
Maximum output (L/day)3800 L/day
Output of the entry-level model (L/day)1900 L/day
Water produced
Salt rejection, at best (%)99 %
Water discarded per litre produced1 to 1.5 L
Installation
Works without a power socketNo
Automatic production cut-offYes
Built-in water quality monitoringNo

Manufacturer values noted on 20/09/2026 from the ARKA and Dupla product pages, supplemented on 11/10/2026 from the ARKA myAQUA 400 and 3800 pages. The stated output is a maximum, achieved at favourable pressure and temperature.

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delivery time

Lightweight parcel, dispatched within 48 hours by Colissimo or Chronopost to your home, as you choose at payment. The exact cost depends on the method selected.

Frequently asked questions

8 questions

6 key questions, 8 in the detailed view

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