What are legionella

Protection thanks to an innovative legionella filter and sterile filter

Legionella – The invisible danger in warm water

A barely visible but serious health risk hides in tap and shower water: Legionella. These bacteria multiply most effectively in warm, stagnant water — for example, when hot water temperatures are too low, pipes are rarely used, or in so-called dead legs. A biofilm forms on the inner surfaces of the pipes, providing an ideal environment for Legionella to settle and grow. When showers or faucets are turned on, the bacteria enter the water and can be inhaled through fine mist or aerosols.

Why are legionella dangerous?

In small amounts, Legionella are usually harmless. They become dangerous when they enter the air as tiny water droplets from the showerhead and are inhaled. In particular, the species Legionella pneumophila can cause serious illnesses such as Legionnaires’ disease or the milder Pontiac fever. The illnesses often begin with flu-like symptoms but can develop into severe pneumonia, which can be fatal in up to 15% of cases.

According to estimates by the Robert Koch Institute, up to 3,000 deaths in Germany each year are attributed to Legionella – a risk that can be significantly reduced with proper preventive measures.

How does a Legionella / sterile filter provide protection?

A Legionella filter / sterile filter is the most effective immediate measure to protect against these pathogens. The filter membrane has tiny pores of no more than 20 nanometers—too small for Legionella or other microorganisms to pass through. This way, only clean water passes through the filter, while the bacteria are safely retained.

Point-of-use Legionella filters, i.e., sterile filters installed directly on the faucet or showerhead, stop transmission immediately. They can be installed without tools and provide instant protection—even in buildings where a shower ban has already been imposed by the health authorities. After consultation, this ban can often be lifted when a certified Legionella filter is in place.

How can Legionella be prevented additionally?

In addition to filter technology, regular maintenance of the water system plays a crucial role in preventing Legionella. The bacteria thrive especially well in lukewarm, stagnant water. By setting the hot water system to at least 60 °C, keeping cold water pipes cool (below 25 °C), and regularly flushing rarely used lines, the growth of Legionella can be significantly reduced. Removing dead-end pipes and routinely checking drinking water hygiene are also important measures to prevent Legionella from developing in the first place, including in showerheads.

Where are Legionella / sterile filters used?

Legionella filters are suitable for almost all areas where water comes into contact with people:

  • Healthcare: hospitals, nursing homes, rehabilitation and spa facilities, medical practices, dental practices
  • Public buildings: schools, gymnasiums, swimming pools, sports facilities
  • Private use: single-family homes, rental apartments, holiday homes

They provide protection wherever hot water is used—especially when showering. In private settings, they offer a sense of safety and hygiene in the bathroom.

How long does a Legionella filter last – and what should be considered when replacing it?

A high-quality Legionella filter / sterile filter typically remains fully effective for 70 days to three months, depending on water quality. Products with CE Medical Class 1 certification ensure the highest safety: an integrated check valve prevents filtered bacteria from flowing back into the water system.
After the filter’s lifespan expires, the cartridge can be easily replaced—especially convenient for a Legionella showerhead or sink faucet where the filter is integrated directly into the device. Replacement requires no tools and takes only a few minutes.

Sustainability and disposal of Legionella filters

Used filters should be disposed of properly after replacement.
The Acquaspar Legionella filter systems are designed so that only the filter cartridge needs to be replaced, while the housing can be reused. This reduces plastic waste and makes protection against Legionella more environmentally sustainable.

What else does a Legionella filter remove?

In addition to Legionella, the fine filter membrane of sterile filters also removes other harmful bacteria such as Pseudomonas aeruginosa, Citrobacter koseri, and Escherichia coli (E. coli), which can also cause infections.
This makes the water not only germ-free but also significantly more hygienic, providing an important contribution to health safety.

Guaranteed protection against Legionella

Acquaspar offers solutions for Legionella-free tap water.

A Legionella filter is a simple, immediately effective solution to protect yourself and others from harmful germs in the water. It reliably prevents Legionella from being inhaled through the showerhead or faucet, especially when showering. Regular filter replacement ensures lasting protection—providing clean water, improved hygiene, and greater safety in everyday life.

Acquaspar supports you in implementing legal requirements and offers modern solutions for reliable protection against legionella: from self-cleaning legionella filters and ultrafiltration systems to rapid tests for microbiological monitoring.

Our products are ideal for hospitals, care facilities, hotels, schools and industrial buildings – wherever water hygiene is a top priority.

Put your trust in Acquaspar – for clean water and sustainable safety.

Legionella filters and rapid test

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Legionella Filter & Sterile Filter

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Acquaspar - Legionellenfilter - Selbstreinigender Legionellenfilter Kaltwasser

Self-cleaning legionella filter

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Legionellen Schnelltest - Hydrosense Pro Ultra

Legionella rapid test Pro Ultra

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Why you should choose Acquaspar?

With many years of experience in water treatment, Acquaspar is your reliable partner for customized and innovative solutions. Our goal: sustainable water quality and maximum safety for people and systems.

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