Spa sanitizers

Chlorine is considered too high in a spa when the level goes above about 5 ppm. At this point, the water becomes less comfortable—stronger odor, eye irritation, and dry or itchy skin. If the chlorine level reaches 8 to 10 ppm, it’s best to avoid using the spa until the level drops.

To lower high chlorine, simply leave the spa uncovered so the chlorine can naturally dissipate. Wait a few hours, then test the water again to confirm that the level has returned to a safe range.

Add your sanitizer according to the type you use, then test the water. Aim for 3 to 5 ppm, whether you’re using chlorine or bromine.

• Granular chlorine: add a small dose directly into the water with the jets running, wait 10–15 minutes, then test again.
  
• Chlorine or bromine tablets: place them in a floater and adjust the opening to control how quickly they dissolve.
  

If the sanitizer level stays low even after adding product, perform a shock treatment—chlorine shock for a chlorine spa, or a non-chlorine oxidizing shock for a bromine spa.

Both chlorine and bromine disinfect spa water very well.

• Chlorine: cheaper, acts quickly, but stronger odor and less stable in hot water.
• Bromine: more stable in hot water, less odorous and more comfortable for the skin, but a little more expensive.
  
  

It is not recommended to mix chlorine and bromine in a spa because these sanitizers react chemically when combined. This can create unstable water, sudden fluctuations in sanitation levels, and even reduce the effectiveness of both products.

If you want to switch from chlorine to bromine (or the opposite), you must fully drain the spa, clean the shell, and rinse the filters to remove all traces of the previous sanitizer. Once the spa is refilled with fresh water, you can start your new maintenance routine. Mixing chlorine and bromine in the same spa is never recommended.

Chlorine comes in tablets or granules.

- Lozenges: preferably placed in a floating dispenser (or directly in the water if the manufacturer allows it). Allow approximately 1 lozenge per day, and less if you accompany your routine with a shock treatment. For slow-dissolving lozenges, plan on 3 to 5 lozenges per week in a floater, and less with a shock treatment.

- Granules: add once a day, unless accompanied by a shock treatment, which helps the chlorine level to be maintained for longer.

These amounts are averages: actual use of your spa may vary requirements, but they give a good idea to start with.

Tablets: must be placed in a floating dispenser (not directly in the skimmer unless otherwise indicated by the manufacturer). For slow-dissolving tablets, plan on 2 to 3 tablets per week in a float, and less if you accompany your routine with a chlorine-free oxidant, which activates the bromine and reduces consumption.

Granules: Add once a day, unless accompanied by an oxidizing treatment, which helps maintain bromine levels for longer.

These amounts are averages: actual use of your spa may vary requirements, but they give a good idea to start with.

The amount of chlorine to add depends on the volume of your spa and the measured chlorine level. Generally, you would add 1 to 2 chlorine tablets or approximately 10 to 20 grams of granular chlorine for a 1,000-liter spa. The goal is to maintain a free chlorine level between 3 and 5 ppm to ensure effective disinfection. It is recommended to always consult the manufacturer's chart and test the water regularly to adjust the dosage as needed.

Although pool chlorine is chemically similar, it is not recommended for use in a spa. Pool products are often more concentrated and designed for large volumes of water, which can make dosing in a spa much more difficult and risk irritation or over-chlorination. Spa products are formulated for high temperatures and smaller volumes, allowing for more precise and safer control.

To add chlorine to a spa, first test the water to determine the current level. Then add the recommended dose of granular chlorine directly to the water or chlorine tablets to the dispenser/float provided. It is important to let the pump run for at least 15 to 20 minutes after adding the chlorine to ensure proper dispersion. Wait until the chlorine level drops back into the safe range before using the spa.

To switch from chlorine to bromine, you must first completely drain the spa, clean the tub, and rinse the filter to remove all traces of chlorine. Once the spa is filled with fresh water, place bromine tablets in the float or designated dispenser. A shock treatment with active oxygen can help quickly establish the bromine level. This changeover must be done carefully to avoid chemical reactions between the two products.

Yes, a spa should always be disinfected with a sanitizer such as chlorine or bromine. The high temperature of a spa (around 37–40°C) promotes rapid bacterial growth, so maintaining a consistent level of disinfection is essential. Chlorine is effective, economical, and acts quickly, but bromine is more stable in warm water. The choice depends on the owner's preference, but a spa should never be operated without a sanitizer.

The amount of bromine to add depends on the volume of your spa and the measured level in the water. Generally, 2 to 3 bromine tablets in a floater are used for a 1,000-liter spa, which maintains a bromine level between 3 and 5 ppm. If you are using granular bromine, you usually add between 10 g and 20 g to quickly adjust the level. Bromine is more stable than chlorine in warm water, but it should still be tested regularly to ensure consistent and safe disinfection. Ideally, an oxidizer (such as a chlorine-free shock treatment) should also be used in addition to bromine to burn off impurities and keep the water clearer. Always refer to the manufacturer's guidelines to adjust the dosage to the volume of your spa.