Last updated: August 6, 2021

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Drinking water filters ensure that you can drink your drinking water without any adulteration of taste. Although you can drink tap water with a clear conscience, harmful substances get into the groundwater and thus also partly into our water pipes. A drinking water filter frees the water from these harmful substances. With our drinking water filter test 2021 we want to help you with your decision and present the best drinking water filters on the market. For this purpose, we have looked at various drinking water filters and selected facts on the decisive properties of drinking water filters for you.


  • Drinking water filters free tap water from annoying calcifying and harmful substances. The resulting high quality of drinking water makes a difference in taste. Drinking water filters are either permanently installed under the sink in the kitchen or at the tap.
  • Coffee and tea drinkers in particular are delighted with the visual improvement of the drinking water. The filtered water ensures that there are no unsightly streaks on the surface of hot drinks.
  • The drinking water filter must be cleaned regularly to prevent the formation of germs and to ensure the high quality of the drinking water. By simply changing the cartridge, you don't need much time to clean your drinking water filter.

The Best Drinking Water Filter: Our Picks

Buying and evaluation criteria for drinking water filters

We would like to show you the variety of drinking water filters on the basis of different aspects. Depending on your needs and requirements for your desired drinking water filter, you can choose between different types and processes. In summary, these are the following criteria:

In the following, we will explain what these types and processes are all about to help you choose the right drinking water filter for you.

Built-in drinking water filter

Built-in drinking water filters are so-called under-sink water filters that are connected to the water connection under the sink. The built-in drinking water filter, as the word suggests, is not a portable drinking water filter. The built-in filter can be installed in such a way that you already use the existing tap. However, you can also have an additional tap installed so that you can distinguish between drinking water and service water. Dirty dishes can be washed better with service water, because the dirt dissolves better with water containing lime.

Mobile drinking water filters

The choice of a suitable mobile drinking water filter depends on whether you want to filter your water at home or on the road. A distinction is made between the following three mobile drinking water filters:

  • Table water filter
  • Bottle filter
  • Water filter for the tap

On the one hand, there is the mobile table water filter. Although this is mobile, it is mostly used for normal household use. The table water filter has the shape of a jug into which several litres of water can be filled. The practical and handy shape makes it possible to store the jug in the refrigerator. Another mobile drinking water filter is the bottle filter. The bottle filter is one of the smallest types of drinking water filters. Bottle filters can usually hold no more than 0.5 litres of water. Because bottle filters are small, they can be easily refilled at the tap. They can easily be carried in a backpack or handbag. The third mobile drinking water filter is the drinking water filter for the tap. The drinking water filter is simply attached to the tap. So you can enjoy filtered drinking water all the time.

The drinking water filter for the tap is suitable for taking along on trips.

With a drinking water filter for the tap, you save space in the fridge or on the worktop in the kitchen.

Filtering methods

There are different filtration methods, depending on the type of drinking water filter system. The choice of filtration method depends on how pure you want your water to be. We would like to introduce you to the individual processes in the following. Activated carbon filter: The activated carbon consists of small pores through which the water flows. The unwanted substances settle in the pores. The substances remain in the drinking water filter until the cartridge is changed again. Ion exchanger: In the ion exchanger, inorganic particles are exchanged for others. For example, calcium or magnesium ions, i.e. lime, are removed from the water and exchanged for sodium ions. Reverse osmosis: In this filtering process, impure water is forced through a membrane with the help of pressure. If it is important to you that limescale in the water is reduced, then you should opt for an ionic autoclave or a reverse osmosis drinking water filter. However, lime is not harmful to human health. Therefore, you can also choose a filter with an activated carbon filter with a clear conscience.

Guide: Questions you should ask yourself before buying a drinking water filter

We would like to answer all relevant questions about drinking water filters before you buy. In the next sections, we will go into the essential details so that you know all the information about the drinking water filter.

What is special about a drinking water filter and what advantages does it offer?

Although tap water can be drunk with a clear conscience, harmful substances can get into our domestic water pipes. Groundwater is contaminated by fertilisers, for example, and gets into our tap water. Despite measures, the waterworks cannot filter out all pollutants. The special feature of a drinking water filter is that it can filter out the pollutants left behind. It frees the drinking water from limescale and heavy metals, among other things. Drinking water filters offer you many advantages due to the improved water quality:

  • less limescale and therefore softer drinking water
  • sustainable and environmentally friendly lifestyle
  • taste improvement
  • optical improvement due to softer drinking water

The drinking water filters make the drinking water softer and when preparing hot drinks, there are no streaks on the surface of your coffee or tea.


A drinking water filter helps to improve the appearance of the water, as most filters significantly reduce the limescale in the water.
(Image source: Chris Ralston / unsplash)

Drinking water filters contribute to a sustainable lifestyle by reducing the consumption of purchased plastic water bottles. Another advantage is that due to the high water quality, an improvement in taste is also noticeable. By getting rid of limescale, you protect your household appliances from calcification. Even your sensitive plants can be watered with the lime-free water without any problems.

What types of drinking water filters are there?

There are three different types of drinking water filters and filtering methods. In the following, we would like to introduce you to the different types of drinking water filters and their advantages and disadvantages.

Activated carbon drinking water filter

One type of drinking water filter is the activated carbon drinking water filter. The water flows through small pores in the activated carbon. The pollutants settle in the pores.

  • Taste improvement
  • Very good pollutant retention
  • Important minerals remain in the water
  • Rapid germ formation if not used
  • substances such as lime remain in the water

An activated carbon drinking water filter filters out chlorine and many organic substances such as pesticides. Nevertheless, minerals, salts and lime remain in the water. If the drinking water filter is not used for a longer period of time or if the water stands in the container, there is a risk that germs will multiply in the water.

Ion exchange drinking water filter

Another type of drinking water filter is the ion exchange drinking water filter. With this type of filter, inorganic particles are exchanged for other particles.

  • Taste improvement
  • Very good pollutant retention
  • No limescale in the water and thus visual improvement and protection of household appliances
  • Can suddenly release retained ions into the water
  • rapid germ formation if not used

Ion exchangers filter many unwanted substances out of the water. Limescale is also removed from the water. However, there is a danger that retained ions are suddenly released into the water. If the filter is not used for a longer period of time, germs can multiply in the water.

Reverse osmosis drinking water filter

With this type of drinking water filter, water is forced through a membrane using pressure. The filter membrane filters almost everything out of the water. Minerals, germs and chlorine are also filtered out by the process.

  • Taste improvement
  • Very good pollutant retention
  • No limescale in the water and thus visual improvement and protection of household appliances
  • High maintenance due to susceptibility to germ formation
  • maintenance requires high water consumption and thus high costs
  • demineralisation

Continuous consumption of this water can deprive the body of minerals such as magnesium and calcium and lead to an undersupply. To prevent the fine filter membrane from becoming clogged, it has to be rinsed using a lot of water. This results in high energy and water costs. Usually, several types of filtration processes are installed in a drinking water filter to ensure optimal filtration. One type of drinking water filter is thus complemented by the use of several processes.

For whom are drinking water filters suitable?

Drinking water filters are suitable for a wide variety of situations. They range from built-in drinking water filters at home to outdoor drinking water filters, which can be filled up with water from natural waters without any worries. So it depends on you whether you want to improve the quality of your drinking water in your own household or whether you are looking for a drinking water filter for on the road. The table we have compiled should help you make your choice:
Use Type of drinking water filter
Improving water quality at home Built-in drinking water filter, drinking water filter for the tap or table water filter
Travelling with a caravan or staying in a hotel Table water filter or drinking water filter for the tap
Hiking trips, backpacking, sports or otherwise on the road Bottle filter

If you want to increase the quality of the drinking water in your home, we recommend that you have the water tested beforehand. This can be tested directly by the municipal waterworks or by an independent institute. If you need a drinking water filter for travel or excursions, then a bottle filter is the optimal choice for you. If you want to improve the water quality in your home, we recommend a built-in drinking water filter, a drinking water filter for the tap or a table water filter.

How do I clean a bottle filter or a table water filter?

Regular and correct cleaning is important to counteract the formation of germs and bacteria on the filter. The measure for keeping your drinking water filter clean is to change the cartridge. The cartridge is changed as follows:

  1. Pour the remaining water out of the jug or bottle.
  2. Open the lid of the filter insert and remove the old cartridge
  3. Insert the new cartridge.
  4. Clean the housing of the drinking water filter.
  5. Run water through the drinking water filter a few times so that the filter material is soaked.
  6. Return the used cartridges to the dealer or a specialist company.

The cartridge should be changed every four weeks when in use. This applies to both table water filters and bottle filters. Some drinking water filters have a filter change indicator that shows when it is time to change. The water in table water filters or bottle filters should not be left to stand for several days, otherwise germs may form. Even when using tap water, the stagnant water should first flow out. To do this, open the tap for several seconds so that the tap water can run through.

Are there drinking water filters that produce carbonated water?

Basically, only built-in drinking water filters with an integrated carbonator can be purchased. The carboniser adds carbon dioxide to the water, creating carbonated water. These are highly priced due to the additional function and cost more than 1,000 euros. The CO2 bottles that have to be purchased as a supplement drive the price up even further. Instead, it is advisable to buy a separate drinking water bubbler, which takes up more space in the kitchen, but is much cheaper at around 50 to 150 euros. Just as with the built-in drinking water filter with carbonator, the CO2 bottles must also be purchased here.

A built-in drinking water filter with carbonator saves space, but is more than ten times as expensive as a drinking water bubbler.

The fact that CO2 bottles have to be purchased regularly for both variants makes it clear that the built-in filter with carbonator does not offer any convincing advantages.


With the help of a drinking water filter you can enjoy cleaner drinking water and protect your household appliances from calcification. Your sensitive plants also benefit from the filtered water and can be watered without worry. Drinking water filters score points with their versatile filter options, so that you can determine the intensity of the purification of your water yourself. The fact is that drinking water filters improve water quality not only in your household. With portable drinking water filters, you can enjoy clean water on the go. The fact that you can fill up bottle filters in streams and rivers means that no heavy water supplies stand in the way of your outdoor trips. Picture source: Yastremska / 123rf