Hot tub biofilm – causes, risks & effective control

Whirlpool Biofilm EGO3 Filter

What Is Hot Tub Biofilm?

Hot tub biofilm is an accumulation of microorganisms that forms on the surfaces of hot tub systems—particularly inside the pipes. These biofilms consist of bacteria, algae, and other microorganisms that clump together in a slimy layer. They can be unsightly and also pose significant health risks. In addition, living hot tub biofilm continuously releases bacteria into the pool water.

Biofilm is a community of microorganisms that adhere to a surface and form a protective slime layer. This layer protects the microorganisms from external influences such as disinfectants or cleaning agents. This protective layer can only be breached with inorganic chlorine.

How Does Inorganic Chlorine Combat Hot Tub Biofilm?

Inorganic chlorine is the most effective—and the only truly effective—method for combating hot tub biofilm. It kills the microorganisms that form the biofilm and thus prevents further growth. Once the biofilm has been killed, it breaks away from the pipes in white and beige flakes (water pipes) to black flakes (air pipes). These look like soft skin flakes up to 1 cm in size.

Inorganic chlorine only works optimally when the pH value is correctly adjusted. Therefore, precise hot tub water care is particularly important.

Reduce and Remove Hot Tub Biofilm with the EGO3 Filter

The EGO3 filter plays a key role in reducing and removing hot tub biofilm: It filters all impurities from the water, thereby inhibiting the growth of microorganisms. Thanks to its significantly higher flow rate compared with a conventional cartridge filter, the killed biofilm is flushed out of the pipes more quickly and thoroughly.

The combination of regular use of inorganic chlorine and the EGO3 hot tub filter is the most effective method for permanently combating hot tub biofilm, improving water quality, and protecting users’ health.

Back to blog

Hot tub Chlorine – Disinfection for crystal-clear water

Discover our selection of high-quality chlorine products specially designed for hot tubs and Spas. Whether granules or tablets – here you will find the right product for every application.

  • Inorganic Chlorine – Calcium Hypochlorite 1 kg: Fast-dissolving granules for initial dosing and shock treatment. Effectively kills bacteria, viruses, and biofilm.
  • Premium Chlorine – Organic Powder 1 kg: Fast-dissolving premium granules for initial dosing and shock treatment. Effective against fungi, viruses, and organic turbidity – suitable for all water hardness levels.
  • Organic Chlorine – Tablets 20 g, 1 kg: pH-neutral chlorine tablets for continuous and initial dosing. Ideal for floating dispensers, residue-free and low dust.

All products are adjusted to the optimal pH range of 7.0–7.4 and suitable for private hot tub and Spa use. Use biocidal products with caution – always read the label before use.

1 3