What is the best water filter

Water filter: the best models in comparison

The quality of drinking water in Germany is so good that a water filter is usually unnecessary to protect health. If you still want to filter your tap water before you fill it into the water bottle or carafe, we will introduce you to the various technologies and models in our 2021 comparison. You can also find out here which criteria are important in order to select the best water filter for you.

Water filter: the best models in comparison
Water filter: the best models in comparison

Water filter: the most important things at a glance

Despite the very good drinking water quality in this country, there are reasons why you want to filter your tap water again before drinking it: lead pipes in your own house, too high a calcium content, drug residues in tap water or for the preparation of baby food. For this, the manufacturers not only offer water filters of different sizes, but also various technologies. In addition to ion exchangers, which exchange magnesium and calcium ions for sodium ions, there are reverse osmosis filters for osmosis water. The widely used activated carbon filter works in a similar way. The suspended matter contained in the water is deposited in it. In addition, the trade offers filters for different areas of application: table water filters, house water filters, travel filters and filters for taps.

Buying advice for water filters: You should pay attention to this

The ion exchanger removes magnesium and calcium ions from water and thus the lime it contains. They are replaced by sodium ions. In doing so, he removes minerals from the water that are actually very important for the body.

In reverse osmosis, the water is pressed through a membrane. This semipermeable layer is only permeable from one side. It acts like a sieve that removes larger particles such as heavy metals etc. from the water.

Activated carbon filters are porous with a fairly large surface. For example, they absorb bacteria and chlorine from the water.

Water filter in the test comparison 2021: Our evaluation

For our water filter test overview, we have evaluated current tests, customer ratings and comparisons of numerous test magazines and portals, including the Stiftung Warentest. The result is a comparison of the five best water filters. The Brita Marella Cool Water including two Maxtra filter cartridges won the test. It scores with an electronic cartridge change indicator and is partially dishwasher-safe. We were able to choose the BWT 815073 Penguin as the price-performance winner. With a capacity of 2.7 liters, it is also suitable for larger households. Its filler flap enables easy refilling. The other test candidates also have a lot to offer.

Test table



2.4 lplasticYes
  • easy
    Filling opening
  • easier
  • narrow
  • Design,
    fits in
    cabinet door
  • Re-purchase
    of filter


2.7 lplasticYes
  • quality
  • goods
  • electronic
    Filter change
  • at very
    Filter intervals

2.3 L.

2.3 lplasticYes
  • simple
    Hinged lid
  • compatible
    with Amazon
    Basics and
  • included
    Water filter
  • according to users
    mer water
  • Fresh water
    at full
    Jug with


2 lplasticNo
  • optically
    very attractive
  • BPA free
  • little
    Filter capacity
  • removable
    Lid in place
    Lid flap


1 to
1.3 l
  • triple
    Ion output
    High performance
    Activated carbon,
    Pi mineral
  • simple
  • should be loud
    Manufacturer up
    to 99 %
  • expensive
  • Substitute

The test winner in the water filter test comparison: Brita Marella Cool Water

Our test winner Brita Marella Cool Water reliably filters tap water. The results satisfy testers and users alike: water and drinks made from it taste better. Coffee machines and kettles need to be descaled less often. Limescale streaks on dishes and cutlery are a thing of the past. Handling the Brita water filter is child's play. It is filled via a large filler flap in the lid. A maximum of 1.4 liters of filtered water is available after just a few minutes. With its slim design, the container fits in the refrigerator door. Without a lid, the jug can also be put in the dishwasher for hygienic cleaning. According to the manufacturer, the Maxtra cartridges must be changed on a monthly basis. The water filter is equipped with a battery-operated change indicator so that you can keep an eye on it at all times. It only measures the elapsed time, but not the amount of filtered water. Therefore, their function is rather questionable. The comparatively high costs for replacement filter cartridges are negative.

Brita Marella Cool Water in the test

  • 4.6 out of 5 stars on amazon.de
  • 2nd place onvergleich.org
  • Test grade 2.4 ("good") on testreports.de
  • Test grade 3.4 (“satisfactory”) on test.de

The price-performance winner in the water filter test comparison: BWT 815073 Penguin

Our price-performance winner comes from BWT. The BWT 815073 Penguin is characterized by its slim dimensions and low weight. It weighs less than 1 kilogram and, according to the manufacturer, filters around 120 liters of water per filter cartridge. The equipment includes an electronic display when the next cartridge change is due. It was designed to fit in any refrigerator door. The activated charcoal filter is multi-stage. In this way, it not only removes impurities from the tap water. The integrated BWT Magnesium Mineralizer exchanges calcium for magnesium.

All materials of the water filter are BPA-free. Bisphenol A, or BPA for short, is a harmful plasticizer that can be found in many plastics. According to the manufacturer, the water conditioner with activated carbon filter removes heavy metals, lime and chlorine from the tap water. The jug is dishwasher safe up to a temperature of 50 degrees. It is best to clean the lid by hand.

This is what the users say

Amazon customers rate the BWT 815073 Penguin consistently good to very good.

  • 4.5 out of 5 stars on amazon.de
  • Comparison winner on Warenvergleich.de
  • 4th place on sueddeutsche.de

Other well-rated water filters in the test comparison

They free the tap water from heavy metals, chlorine and lime and thus ensure a delicious taste. Not all water filters made it to the podium. Nevertheless, the other test candidates also have a lot to offer.

More interesting test articles

AmazonBasics 2.3 L: Transparent design and attractive price

With its slim shape, the AmazonBasics 2.3 L fits perfectly into the refrigerator door and you have fresh and filtered tap water available at all times. The application is very easy. To fill, simply open the large flap in the lid to let the water flow into the upper container. After a few minutes, up to 1.4 liters are filtered. According to the manufacturer, the water filter removes chlorine, lime and other impurities from the water. It is also very suitable for hard water. The special thing about the water filter is that you can use not only filter cartridges from AmazonBasics, but also the Brita Maxtra filters.

AmazonBasics 2.3 L in the test mirror
Overall, the AmazonBasics water filter scores very well with users. In particular, they describe the handling and the cartridge change as easy. A significant improvement in the water quality was also found.

  • 4.5 out of 5 stars on amazon.de
  • 1st place and "tip" on sueddeutsche.de
  • 6th place on ExpertTesten.de

Stelton 1310-10: Modern eye-catcher for the kitchen

With a total volume of 2 liters, the Stelton 1310-10 has sufficient capacity to always provide freshly filtered water in a multi-person household. With its eye-catching design, it stands out from its competitors in our comparison. It is dishwasher safe and can be equipped with filters of various brands. In contrast to the other test candidates, this water filter does not come with a filter cartridge. Users complain that there are no instructions. This makes the first change of the filter cartridge difficult, especially for those who are new to filter jugs. Another point of criticism is the missing filler flap in the lid.

Stelton 1310-10 in the test mirror
Users on the common sales platforms very often rate the Stelton 1310-10 as good to very good. The attractive appearance of the water filter was particularly praised. It is also very important to users that the product is free from bisphenol A, which is harmful to health.

Acala QuellOne: easy cartridge change

The Acala QuellOne is one of the most expensive water filters in our comparison. In this filter, an integrated micro sponge cleans the water from even the finest particles. The actual filter cartridge contains activated and silver carbon to remove lime, nitrate and other undesirable substances from the tap water. The PI technology developed in Japan and Germany is used. With the help of a magnet and various rocks, the filtered tap water is to be brought to a vibration level with the human body cells. After filtering, it flows through a layer of zeolite and bioceramics. Some users on the Internet confirm an improved taste.

Acala QuellOne in the test mirror

  • 4 out of 5 stars on amazon.de
  • Test grade “very good” on haushaltstipps.net
  • Test grade 2.0 (“good”) on testreports.de
  • 7th place onvergleich.focus.de
  • 9th place onvergleich.org

* All prices as of January 2021