Drinking water in Germany is subject to strict quality standards and can generally be used without hesitation, both for consumption and for personal hygiene. In some cases, however, hot drinking water from the tap or shower can also be contaminated with harmful bacteria – the so-called legionella.

This article shows why the use of a legionella filter makes sense and which types of filters can be used.

What is a legionella filter?

Legionella are bacterial pathogens that find good growth conditions especially in artificial water systems such as water services, boilers, whirlpools and other facilities, where they can successfully multiply at an ideal water temperature of 30 to 50 degrees Celsius. Stagnant, warm water systems are thus ideal foci for the spread of harmful pathogens. Here you can read exactly how legionella is formed in the water pipe.

The small bacteria can enter the lungs through the water vapor and cause lung disease, especially in immunocompromised and elderly people. A legionella filter can remedy this situation and clean the valuable drinking water from the bacteria. Although the filter does not prevent the pathogen from multiplying, it reliably ensures that they do not enter the usable drinking water.

The legionella filters are particularly useful for public facilities, schools, daycare centers or hotels, as the consequences of a legionella infestation can be particularly severe here.

The mode of operation

In order to reliably filter Legionella out of the water, special filter systems are used that have membranes with a very small pore size. The bacteria cannot pass this membrane due to their size and settle there. As a result, the filter only allows clean water to pass through, which can be used without hesitation.

A legionella filter is much more effective against bacteria than a conventional water filter, for example with activated carbon. These usually contain membrane pores that are too large for the small pathogens to pass through without any problems. Instead, legionella filters work with so-called ultrafiltration, in which even the smallest bacteria can be filtered out.

The different types

If the bacterial pathogens occur in one’s own household, the question immediately arises: What to do about Legionella? In the event of a Legionella infestation – but also as a preventive measure – a filter can provide a quick and uncomplicated remedy and ensure the quality of the water.

There are different types of legionella filters, which are suitable for different purposes: Legionella filters for the shower, filters for the faucet, and filters as well as Legionella filters as independent fittings.

The filter is most relevant for the shower, as the risk of disease is highest there. Special legionella filters for shower heads filter the bacteria directly in the shower head and thus provide reliable legionella protection.

A legionella filter as an additional fitting is attached under the actual shower fitting and the shower head is then connected to the filter. Even so, the shower water is effectively filtered and can be used without hesitation.

The filter for the faucet is screwed into the thread of the faucet. Thus, the water flows first through the faucet, then through the filter and finally clean out of the faucet.

Service life of the legionella filter shower head

The service life of a Legionella filter for the shower head depends on the so-called alluvial density. This is reported in the Silt Density Index (SDI) and indicates how many particles are in the water.

The following applies: In principle, legionella filters have a service life of between eight weeks and a few months at an average precoat density. Particularly high-quality legionella filters for the shower, such as the “LONGLIFE” model from Sanquell, can even provide several months of reliable protection against legionella. After this time, the filter should be replaced.

Advantages and disadvantages of a shower with legionella filter

The use of legionella filters brings a number of advantages. But just as in other areas, the same applies here: Legionella filters require some care to ensure that the filter function remains reliable and hygienic.

Advantages

The decisive advantage of a legionella filter is the effective cleaning of the service and drinking water. Good filters remove not only legionella, but also other bacteria, germs and pollutants from the water. This makes the filtered water more suitable for the human body as a whole, and allergy sufferers and people with sensitive skin also benefit from the purity.

In addition, a legionella filter scores with easy installation. Especially the legionella shower head is easy to screw on and immediately ready for use.

Disadvantages

In principle, a legionella filter is a very safe protection against legionella in drinking water. However, as is often the case, there is no guarantee that all bacteria will be filtered out. Therefore, it is important to rely on high-quality, tested products.

Particularly in the case of old, weak and sick persons, therefore, always use as new a high-quality filter as possible, which should be thoroughly cleaned and checked for integrity on a regular basis.

In addition, one should pay attention to a sufficiently high water temperature, with which the harmful bacteria are killed: But which temperature kills Legionella reliably? The following applies: At least 55 to 60 degrees Celsius are required to prevent Legionella and to prevent the pathogens from growing. In case of an already existing legionella infestation, 70 degrees Celsius are useful to kill the bacteria.

FAQ: Legionella filter for the shower

Is it possible to filter legionella?

Legionella can be reliably filtered out of the water by ultrafiltration systems. This requires filters with extremely fine-pored membranes, which the bacteria cannot pass through.

In order for the filter to completely filter out legionella, it should meet government-established quality standards and be cleaned regularly.

How safe are legionella filters?

High-quality legionella filters, such as those from Sanquell, reliably retain legionella and enable safe showering – even for more susceptible groups of people. The fine pores of the filter membrane have a minimal diameter and are therefore impenetrable for Legionella and other germs. It is important that careful cleaning and filter changes are performed regularly.

How long do you have to run the shower with legionella?

Legionella bacteria like to settle in the pipes of the water supply. To ensure that the bacteria are reliably killed, 70 degree Celsius water should be flushed through the pipes over a period of at least 3 minutes. It makes sense to additionally use a high-quality legionella filter to be able to use absolutely hygienic and clean water.

Conclusion

Legionella filters are useful aids to protect public facilities and private households from the dangers of legionella infection. However, when buying it is important to note that the product in question complies with legal standards and has a high quality. This is the only way to ensure that even the smallest microorganisms are filtered out.