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ALFILTRA DUPLEX water softening system

 (50)

UVP €1,499.00 20%
€1,199.20
incl. VAT excl. shipping costs
  Available  -  Delivery between 11/17/25 and 11/18/25

Capacity in m³ x °dH

The capacity depends on your water hardness and water consumption. You can determine the capacity using our capacity calculator or use this rule of thumb:

Water hardness Rule of thumb
Medium-hard water (8–14 °dH) Number of people x 7.5
Hard water (14–21 °dH) Number of people x 10
Very hard water (over 21 °dH) Number of people x 12.5

Example (4 people with water hardness 20): 4 x 10 = 40

Dimensioning the water softening system
20 (1-3 Pers.)

40 (2-5 Pers.)

60 (4-8 Pers.)

80 (bis 19 Pers.)

120 (bis 35 Pers.)

180 (bis 45 Pers.)

240 (bis 65 Pers.)

Connection accessories

Do you need a connection kit for installation?
Please select the appropriate option:

  • Without connection set:
    If you already have a suitable connection fitting and hoses and you do not need any new parts.

  • With connection set (without bypass block):
    If a bypass block is already installed but you need new hoses.
    Included are:

    • two flexible hoses for connection to the system

    • wastewater hose

    • Test set for residual hardness testing

  • With connection set (complete):
    If there is no connection yet.
    Included are:

    • Bypass block (connection fitting)

    • two flexible hoses for connection to the system

    • wastewater hose

    • Test set for residual hardness testing
ohne

inkl. Austausch-Set (ohne Bypass)

inkl. Anschluss-Set

Montageservice

The installation service includes the professional installation of the water softener by our trained fitters.
The price includes:

  • the installation of the connection block

  • the connection to the sewage system

  • commissioning of the plant

  • all necessary materials (e.g. two transition pieces)

  • the journey within Germany

Further information and requirements
ohne

inkl. Montageservice

Advice

Your advantages only with us

  • Excellent expertise for 20 years
  • Highest quality in every component
  • fair price-performance ratio
  • in-house, trained fitters
  • no risk through purchase on account (from 500 €)
  • Free shipping in Germany (from 250 €)
Advice

Contact
You can reach our customer service from Monday to Thursday from 9 a.m. to 5 p.m. and Friday from 9 a.m. to 3 p.m.

DUPLEX water softening system

  • Two-column professional water softener for single-family and multi-family homes
  • Two softening columns for uninterrupted soft water supply and optimal capacity utilization
  • ECO-INJECT economy salting saves up to 50% salt with almost the same capacity
  • Freely selectable capacity depending on your water hardness and consumption
  • Connections: 1" threaded connector made of shatter-proof plastic in professional quality

Our double column water softener DUPLEX is ideal for very hard water and/or high water consumption

This fully automatic, two-column water softener with an electronic, water-flow-controlled CLACK WS1-TT control valve is simply installed in front of your existing domestic water supply. The system utilizes the proven ion exchange process and, if desired, completely removes hardness-forming elements and thus limescale from your tap water. Unlike our basic softeners, the duplex systems have a second softener column. This enables an uninterrupted supply of soft water, as the second column simply takes over during the regeneration phase of the first column. This is particularly advantageous in multi-family homes. An integrated safety float valve protects the salt container from overflow, and the glass-fiber-reinforced pressure tank can withstand pressure surges of up to 16 bar. Thanks to our sophisticated ECO-INJECT SYSTEM, the system saves up to 50% salt while operating at near maximum capacity.

Highlights

  • NEW: Electronically controlled volume control CLACK WS1-TT
  • Two softening columns for uninterrupted soft water supply and optimal capacity utilization
  • ECO-INJECT economy salting saves up to 50% salt with almost the same capacity
  • freely selectable capacity depending on your water hardness and consumption (see above)
  • Connections: 1" threaded connector made of shatter-proof plastic in professional quality
  • Residual hardness continuously adjustable via optionally available connection block with blending device
  • Glass fiber reinforced quality pressure tanks and separate salt tank
  • Plug & Play - The system comes pre-programmed to your home
  • built according to DIN-1988, NFS-certified exchange resin
  • 2-year warranty (up to 7 years warranty with annual maintenance)

Scope of delivery

  • Ready-to-use double water softening system consisting of two pressure tanks filled with special high-performance ion exchange resin and the special control valve CLACK WS1-TT
  • separate brine tank (the separate design allows for better room layout)
  • Safety float valve - Protects against overflow of the system
  • Operating and programming instructions

Please note: This system is delivered without connecting parts and a wastewater hose. These can be found above under Accessories. You'll also find an installation service there, if you require it.

If you would like to know more about how water softening works and the benefits it offers, please visit our water softening information pages .

Installation and maintenance service for water softening systems

Alfiltra assembly team

Upon request, we will install your water softener in your apartment building for a fixed price anywhere in Germany. Thanks to our four locations, we can offer the installation service, including travel, at a competitive fixed price.

Here's how it works:

  • You can order the desired system including installation service in our online shop, by phone or by email.
  • To clear up any potential uncertainties, please send us a few photos of the installation location beforehand.
  • We will contact you by phone to arrange an appointment.
  • Our technician will professionally install the system at your location or in your building.

The Alfiltra quality promise

Highest quality

  • Our systems are made in Germany from our own production.
  • Carefully selected materials for durability and reliability
  • Up to 7 years warranty on selected systems with annual maintenance

Maximum safety

  • Pay conveniently and securely by invoice, without financial risk.
  • Positive customer reviews confirm the high level of satisfaction.
  • Quick and uncomplicated help should anything not be to your satisfaction

Competent team

  • Available throughout Germany for fast and competent service
  • Four locations guarantee personal support and fast response times.
  • If you have any questions or concerns, our support team is always available to help.

Installation and maintenance service for water softening systems

Alfiltra assembly team

If you wish, we can install your water softener at a fixed price within Germany. Thanks to our 4 locations, we can offer the installation service including travel at a reasonable fixed price.

This is how it works:

  • You order the desired system including installation service in our online shop, by phone or by email
  • To eliminate any possible ambiguities, please send us a few photos of the installation location in advance
  • We will contact you by phone to arrange an appointment
  • Our technician will professionally install the system for you

Installation and maintenance service for water softening systems

Alfiltra assembly team

Upon request, we will install your water softener for a fixed price anywhere in Germany. Thanks to our four locations, we can offer this installation service, including travel, at a competitive fixed price.

Here's how it works:

  • You can order the desired system including installation service in our online shop, by phone or by email.
  • To clear up any potential uncertainties, please send us a few photos of the installation location beforehand.
  • We will contact you by phone to arrange an appointment.
  • Our technician will professionally install the system at your location.
PURA water softening system BASIC water softener DUPLEX water softening system LEYCOsoft water softener with DVGW
PURA water softening system BASIC water softener DUPLEX water softening system LEYCOsoft water softener with DVGW
 (12)
 (226)
 (50)
 (2)
Price
UVP €699.00
as of €549.00
incl. VAT excl. shipping costs
  Available

UVP €999.00
as of €799.20
incl. VAT excl. shipping costs
  Available

UVP €1,499.00
as of €1,199.20
incl. VAT excl. shipping costs
  Available

as of €1,649.00
incl. VAT excl. shipping costs
  Available

Salt content (Max.)bis 75 kgbis 75 kgbis 100 kgbis 40 kg
Quantity-controlled regeneration
economical salting
residual hardness adjustable
safety swimmers -
Sloping sewage system -
quality components EU/USA-
Uninterrupted soft water supply-- -
app control---
DVGW certificate---

 4.9 from 5 Stars (50 Reviews)

5 Stars (45)
4 Stars (4)
3 Stars (1)
2 Stars (0)
1 Star (0)

Customer Photos

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Before-Duplex20
Duplex 120 water softening system in an apartment building
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double water softener Duplex 20

Latest Reviews

5.00
Maik W.
Jul 7, 2025
Variant: Duplex 40 water softening system in a worry-free package including installation service
I'm extremely satisfied with the system. From the very first second, it was...
I'm extremely happy with the system. I noticed a huge difference from the very first second.
5.00
Andreas L.
Jun 23, 2025
Variant: Duplex 40 water softening system in a worry-free package including installation service
So far it does what it is supposed to do
5.00
o*************@s********.de
Jun 11, 2025
Variant: Duplex 60 Water Softener Worry-Free Package
Very good product with its own maintenance service and good results...
Very good product with its own maintenance service and good accessibility
5.00
Gordon L.
May 16, 2025
Variant: Duplex 60 WS1-TT Water Softener / Descaling System
Very good system. Installing it ourselves was no problem...
Very good system. Installing it ourselves was no problem.
5.00
Mike B.
May 5, 2025
Variant: Duplex 40 water softening system in a worry-free package including installation service
Great product. Works independently without having to do anything...
Great product. Works independently without requiring any action.
5.00
Peter V.
Apr 18, 2025
Variant: Duplex 40 water softening system in a worry-free package including installation service
Very good and very reliable product
5.00
Annette E.
Mar 16, 2025
Variant: Duplex 40 water softening system in a worry-free package including installation service
The term is still too short to make a final statement...
The runtime is still too short to make a definitive statement. So far, everything's been fine.
5.00
k********@y****.de
Jan 29, 2025
Variant: Duplex 60 WS1-TT Water Softener / Descaling System
I have the product as a second system to supply a large...
I bought the product as a second system to feed a larger pool. It was supposed to be a duplex to reduce the time it took to fill the pool. I had been using a basic system for my house for years and knew that the descaler was of good quality. The salt consumption is extremely economical. Highly recommended!
5.00
Jutta F.
Oct 7, 2024
Variant: Duplex 60 Water Softener Worry-Free Package
Water hardness from 28 to 4 ....Top
show all Reviews

A backwash filter should generally be present in every installation. This filters sediments and solids from the drinking water. If you don't have a pre-filter yet, please order one at the same time.
Primus F backwash filter for the house connection 1''
Primus F backwash filter for the house connection 1''
€189.00
incl. VAT excl. shipping costs
  Available

Primus FK backwash filter 1'' with pressure reducer
Primus FK backwash filter 1'' with pressure reducer
€199.00
incl. VAT excl. shipping costs
  Available

This water treatment system works with the ion exchange process. This means that salt is required to operate. How much salt the system needs depends on the water consumption and water hardness. You can calculate your salt consumption using our online calculator.
Salt tablets for water softeners and ion exchangers 5x 25 kg bags
Salt tablets for water softeners and ion exchangers 5x 25 kg bags
€74.00 (€0.59 / kg)
incl. VAT excl. shipping costs
  Available

This special solution of preservative and demineralized water ensures that the resin of your ion exchanger is refreshed. Use once a year or after the system has been shut down for a long time.
RESIN CLEAN resin cleaner for water softeners 1000 ml
RESIN CLEAN resin cleaner for water softeners 1000 ml
€19.90 (€19.90 / l)
incl. VAT excl. shipping costs
  Available

RESIN CLEAN resin cleaner for water softeners 5000ml
RESIN CLEAN resin cleaner for water softeners 5000ml
€89.00 (€17.80 / l)
incl. VAT excl. shipping costs
  Available

Ideal for connecting to an existing connection fitting. Please make sure to order two hoses (inlet and outlet).
Reinforced hose / flexible hose 1'' (75 cm long) for drinking water
Reinforced hose / flexible hose 1'' (75 cm long) for drinking water
as of €30.00
incl. VAT excl. shipping costs
  Available

Reinforced hose / flexible hose 1'' (100 cm long) for drinking water
Reinforced hose / flexible hose 1'' (100 cm long) for drinking water
as of €42.00
incl. VAT excl. shipping costs
  Available

Reinforced hose / flexible hose 1'' (150 cm long) for drinking water
Reinforced hose / flexible hose 1'' (150 cm long) for drinking water
as of €57.00
incl. VAT excl. shipping costs
  Available

Ferromagnetic ring isolated on white background
How does electromagnetic water softening without salt work?

Physical water softening with magnets or electricity? Find out how these processes work and whether they are really effective.

Hartes Wasser
At what level of hardness is a decalcification system worthwhile?

At what level of hardness is a decalcification system worthwhile? Find out at what water hardness a water softening system is worthwhile (from…

Schematische Darstellung
Sodium content when softened by ion exchange

Sodium content when softening by ion exchange: Find out how the water softener exchanges calcium and magnesium for sodium and reduces the drinking…

Wie laut ist eine Enthärtungsanlage bei der Regeneration?
How loud is a softening system during regeneration?

How loud is a softening system during regeneration? Find out how quiet a softening system really is and whether it causes additional noise during…

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Do you have questions?

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Ask a question about this product

Product: DUPLEX water softening system

152 upvotes 1 answers
Answer:
0
Yes, we would be happy to offer you a suitable maintenance contract.

1 upvotes 1 answers
Answer:
0

Yes, our duplex systems are perfect for such applications.

The duplex can manage apartment buildings with irregular water consumption, large garden irrigation, pools, etc. without any problems. However, it depends on the right capacity.

You can either use our calculator or we will be happy to make you a suitable offer and find the right system for you.

0 upvotes 1 answers
Answer:
0

The DUPLEX softening system is designed so that the wastewater resulting from regeneration is drained away efficiently, even without the use of an additional pump. Thanks to the plant's advanced design and efficient use of existing water pressure, it is able to pump wastewater to a height of up to 2.5 meters.

This capability allows for flexible installation of the system as the wastewater hose can be connected directly to a higher wastewater pipe without the need for additional pumping devices. This represents a significant advantage by expanding installation options while keeping operating costs low as no additional energy is required for a wastewater pump.

However, please use an open system such as a funnel for the wastewater connection (the hose must be attached to prevent it from slipping out).

0 upvotes 1 answers
Answer:
0
There are a few requirements that must be met so that the resin is not damaged (for example the correct pH value). For this reason, the systems are generally only suitable for drinking water. However, the exact values are important and there are options to adjust the values beforehand if desired. In such cases, we would be happy to make you an individual offer.

0 upvotes 1 answers
Answer:
0
This is usually 1 - 1.5 meters long. If necessary, we can also extend this individually, but it should not exceed a length of 3 meters.

0 upvotes 1 answers
Answer:
0

For a 4-person household with a water hardness of 18-20 °dH, the basic system is generally an efficient choice, especially if there are no large consumers such as a pool. The Basic 40 offers an optimal solution for your needs as it is specifically tailored to water softening in households.

However, it is important to remember that the choice of investment should also take future needs into account. If there is a possibility that additional people could be added to your household, it is advisable to consider a system with a higher capacity to ensure efficient water softening in the long term.

In short, the Basic 40 is a solid and cost-effective choice for your current needs, but the decision should also take potential future needs into account.

0 upvotes 1 answers
Answer:
0
With the Duplex 20, around 1 bag of salt (25 kg) fits into the salt container (Duplex 40, 60 and 80: 3 bags, Duplex 120 and 180: 4 bags). You will also find this information clearly presented in the technical data sheet for the respective system.
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