Legionella: The hidden danger in whirlpools

In a world where health and safety awareness is constantly growing, it is imperative to be aware of the risks and protective measures in relation to common hazards such as hot tubs. This article provides a comprehensive insight into the dangers of legionella in hot tubs and presents practical solutions to minimize these risks.
What is legionella?
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What is Legionella?

Legionella are a genus of bacteria that are common in natural water reservoirs, such as ground and surface water. They thrive in a variety of humid environments, including the tap water in our homes. Especially in stagnant water with temperatures between 25 °C (77 °F) and 55 °C (131 °F), Legionella find optimal conditions for their multiplication. This characteristic makes them a potential risk in environments such as hot tubs, where warm, stagnant water provides an ideal habitat for their growth.

The risks of Legionella

Although Legionella bacteria in water are usually harmless, their transmission to the lungs, often through inhalation of water vapor, poses a significant health risk. They can cause serious illnesses, especially in people with weakened immune systems, including Legionnaires’ disease, a particular form of pneumonia. This disease occurs when the bacteria enter the lungs after being inhaled and cause infections, which can occur particularly in environments with fine water mist, such as showers or hot tubs.

Ways in which legionella bacteria enter whirlpools

Legionella bacteria enter hot tubs in different ways. These bacteria are naturally present in almost all water sources. In addition to their natural occurrence, legionella bacteria can also enter the hot tub from various external sources. These include refilled rainwater or stagnant water from containers such as buckets and hoses. The bacteria can also enter the pool via the skin of bathers, especially if they have previously come into contact with contaminated water surfaces. This variety of transmission routes shows how important it is to take careful hygiene measures in and around hot tubs.

Effective preventive measures against legionella in hot tubs

Even though it is almost impossible to completely eliminate legionella, targeted measures can significantly reduce its presence and spread in hot tubs.

  • Avoiding stagnant water: To avoid the accumulation of stagnant water, which is an ideal environment for Legionella, it is advisable to leave the outside tap running for a few minutes before filling the hot tub. This ensures that fresh and flowing water enters the pool.
  • Hygiene rules for bathers: One of the most effective ways to reduce the risk of legionella is to shower before entering the hot tub. This removes body oils, sweat and cosmetic products that could serve as a nutrient source for legionella.
  • Choosing the right hot tub: A high-quality hot tub equipped with an ozone purification system and an automatic rinse program can significantly reduce the risk of Legionella contamination. These systems help to keep the water clean and free of contaminants, making it more difficult for legionella to grow.

Advanced protective measures against legionella

  • Thermal disinfection: One of the most effective methods of combating legionella is to heat the water. Heating the water to at least 60 degrees Celsius effectively kills the legionella bacteria. This method of thermal disinfection is particularly effective as it kills the bacteria directly and quickly without the need for additional chemicals.
  • Chemical disinfection: Another option for combating legionella is the continuous chemical disinfection of the water system. Various chemicals approved for this purpose can be used. However, when using such disinfectants, it is essential that the legally prescribed limits and recommended guidelines are adhered to in order to ensure both the effectiveness of the disinfection and the safety of bathers.



The risk of legionella in hot tubs should not be underestimated, but with careful planning and hygiene measures, the risk can be significantly reduced. If you are aware of these risks and take preventative measures, you can enjoy the pleasure of a whirlpool safely and in a healthy way.

Product recommendation: Whirlpool disinfectant

This hot tub sanitizer provides a comprehensive solution for water care in hot tubs, pools, wading pools and whirlpool baths. It is specially formulated to effectively eliminate germs, bacteria, fungi, legionella and other microorganisms and helps to keep the water hygienic. This cleaner is not only suitable for conventional whirlpools and bathtubs, but also for inflatable pools and paddling pools. It prevents unpleasant odors and enables cleaning and disinfection in one step. The liquid cleaner can be used both in combination with chlorine and as a chlorine substitute, making it a versatile and practical option for the care and maintenance of wellness and spa facilities.

KaiserRein 1 L und 5 L Whirlpool Desinfektionsmittel für...


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