What care products do you need for your outdoor hot tub?

An outdoor hot tub in the garden is a wonderful way to relax and enjoy nature. The right water care is essential to ensure that the pleasure remains untroubled and that you can enjoy your hot tub for a long time. But with so many products on the market, it's easy to lose track.

In this guide, you will find out which care products you really need to keep your hot tub water crystal clear and hygienically clean.

Disinfection: the basis of hot tub care

Disinfection is at the heart of water care. It prevents the proliferation of bacteria and germs that can lead to health problems. The most common disinfectants include

  • Chlorine: Inexpensive, quick and effective, but must be topped up regularly as it breaks down quickly in hot water.

  • Bromine: Slightly more expensive, but longer lasting and less odorous. It does not need to be dosed after each use.

  • Mineral disinfectants: Work slowly and are usually used in combination with chlorine.

  • Biguanides: Odorless and effective, but more expensive and potentially harmful to some spa components.

  • Salt electrolysis: Converts salt to chlorine or bromine and provides softer water with less chloramine formation.

Important: Never use different disinfectants at the same time as this can trigger dangerous chemical reactions!

Keep pH value and alkalinity in balance

The pH value indicates how acidic or alkaline the water is. The ideal range for whirlpool water is between 7.0 and 7.4. An unbalanced pH value can:

  • Reduce the effectiveness of the disinfectant,

  • cause skin irritation,

  • and damage the whirlpool tub.

The alkalinity stabilizes the pH value and prevents fluctuations. The optimum range is between 125 ppm and 150 ppm.

Products for regulation:

  • pH raiser (pH+): Increases the pH value if the water is too acidic.

  • pH reducer (pH-): Lowers the pH value if the water is too alkaline.

  • Alkalinity increaser: Stabilizes the pH and increases alkalinity if necessary.


Calcium hardness: Protection against corrosion

Calcium hardness indicates the amount of dissolved calcium in the water. Water that is too soft can corrode metal components in the whirlpool tub, while water that is too hard causes limescale deposits.

The ideal range is between 175 ppm and 250 ppm.

Product for regulation:

  • Calcium chloride: Increases the calcium hardness if it is too low.


Shock treatment: For crystal clear water

Regular shock treatment removes organic impurities, reactivates the disinfectant and ensures hygienically pure water.

Types of shock treatment:

  • Chlorine/bromine shock: Effective, but can lead to chloramine formation, which causes unpleasant odors.

  • Chlorine-free shock treatment: Gentler on the skin and odor-free.

When shock treatment makes sense:

  • After every refill.

  • Once a week for intensive use.

  • After heavy rain or storms.

Optional care products for additional comfort

In addition to the basic products, there are some optional care products that can make water care easier and improve the bathing experience:

  • Water conditioners: Reduce the need for chemicals, but are not essential.

  • Pipe cleaners: Remove deposits in the pipes.

  • Aroma and fragrance additives: Add pleasant fragrances to the water. Make sure that they are suitable for whirlpools.

  • Flocculants (Whirlpool Water Clear): Bind the smallest dirt particles that are not captured by the filter.

  • Enzymes: Break down organic impurities and support the disinfectant.

  • Limescale protection: Prevents limescale deposits on whirlpool tub surfaces.

  • Anti-foaming agent: Removes unwanted foam in the water.

Testing the water: the key to correct dosing

To be able to dose the care products correctly, you need to test the water values regularly.

Options for water analysis:

  • Test strips: A simple and inexpensive method for the most important parameters.

  • Liquid test kit or digital tester: For more precise results.

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