A lot of folks have asked me this same question, ‘Can I use hydrogen peroxide in my hot tub?’ The simple answer to that is ‘NO’. Hydrogen peroxide is not meant to be used in a hot tub, except the manufacturer specifies so.
Hydrogen peroxide is an oxidizer that is not good for hot tub treatment. Simply put, hydrogen peroxide is not a hot tub sanitizer and shouldn’t be used in a hot tub. Consistent use can burn the lung or eye tissues. So you can’t use hydrogen peroxide in your hot tub.
If you are currently using hydrogen peroxide, you need to read this article to know what is best for your hot tub.

I remember the day my cousin Maya and I drove to the spa shop to get some items for our hot tub. While I requested bromine as a sanitizer for my hot tub, she asked for hydrogen peroxide.
I was stunned when I heard that. It dawned on me why she always complained about skin burns most of the time. Well, she didn’t know better since hydrogen peroxide was what her first spa dealer introduced to her as a sanitizer for her hot tub.
This piece is here is educate you on why you cannot use hydrogen peroxide in your hot tub. You will learn the best alternative if you need a sanitizer for your hot tub.
What is hydrogen peroxide?
Hydrogen peroxide is an oxidizer (it can oxidize other chemicals) that has bleaching and disinfecting properties as well. It is mostly used as a sterilizing substance for wounds and cuts. When it comes to water treatment, it is only good for wastewater treatment as it helps to oxidize organics.
Can I use hydrogen peroxide in my hot tub?
No, hydrogen peroxide is not suitable for a hot tub as a sanitizer. It is a well-known fact that hydrogen peroxide can be used in the hot tub mainly as a sanitizer. But, hydrogen peroxide isn’t right for your hot tub water. It is a substance that has the properties to treat wounds or cuts but not a good sanitizer for hot tubs because of the following reasons.
It is hazardous:
Hydrogen peroxide is a powerful oxidizer that has a strong concentration that is between the ranges of 30-50%. With this level of concentration, it is really dangerous to handle. Even when transporting, handling, or storing it, you need to be extremely careful. Without adequate care, a user might easily encounter severe burns, inhalation hazards (it can damage the lungs), and fire. So high level of caution is needed to handle this chemical.
It is an unstable disinfectant:
When it comes to hot tub disinfection, it needs ongoing purity to protect the health of the users. This is because harmful viruses, micro-organisms, and bacteria are most times introduced into the hot tub.
Oftentimes, these microbes come from the users, especially from those that don’t take a bath before a soak in the hot tub. So, if a reliable and stable sanitizer isn’t used, there will be high multiplication of these micro-organisms. Hydrogen peroxide is one of such chemicals. It is not stable, and hence, cannot contend with the harmful microbes.
It causes harm to users:
Since hydrogen peroxide evaporates fast (it is not stable and doesn’t last long in hot tubs), it makes the microbes grow rapidly in the hot tub. This affects the health of the users.
A bacteria-infested hot tub is really bad for the skin. It leads to itching, irritability, and skin infection, popularly known as hot tub rash (hot tub folliculitis).
Moreover, when there’s a high level of hydrogen peroxide in the hot tub, it can burn the tissues of the lungs and eyes. Inhaling it when in the hot tub for a long time can damage the lungs.
If the water with a high dose of hydrogen peroxide is splash on the eye it can burn the cornea. And again, if the hydrogen peroxide water used is above 200ppm it can cause really bad irritation to the skin.
It facilitates a high level of damage to the filters:
Reliable hot tub sanitizers (like bromine) strongly battle the bacteria and other organisms that infiltrate the hot tub. This will help in reducing the pressure and work on the filters. But this becomes difficult to achieve when hydrogen peroxide is used as a sanitizer.
It hardly tackles bacteria efficiently, and as such, more bacteria are led into the water again. With the high amount of microbes entering the water, the filtration system may not function as effectively as it should. As a result, there will be a buildup of pressure on the filter system which may damage the filters and other components.

Is hydrogen peroxide safe for hot tubs?
Like I have earlier stated, it isn’t good to use hydrogen peroxide in your hot tub. But if you still want to use it, you need to follow the tips below:
Start with shocking your hot tub:
For safety, you need to shock the water in your hot tub first with a high dosage of hydrogen peroxide. For every 1000 liters of water add a dose of 250ml.
Let the hot tub stand for about a day. Ensure the circulation pump runs intermittently. You can clean the filters and check them frequently to see there’s no dirt on them.
Maintain a good level of the chemical (hydrogen peroxide):
You should always maintain the hydrogen peroxide level in your hot tub. You can calculate the amount to be used by considering the number of people using the bath, the quality of water used, the amount of sunlight the tubs get, and the frequency of use.
When you get the right quantity for your hot tub, also make sure to be checking the level regularly to know when to add and the amount to add again.
When the level falls to about 50ppm, you should add up to 250ml of hydrogen peroxide (this is like a cup of the chemical per 2000 liters of the water or 500 gallons). This will move the level up to 100ppm. Then try to maintain the levels between 50 -100pmm.
Store and handle with care:
Hydrogen peroxide is corrosive for hot tubs. It can cause burns. So, it should be handled with extreme care. Store it in a very cool and ventilated area. Remember to keep it away from your kids. The vapor from it can be highly irritating, so make sure you keep it away from hair, skin, and eyes.
Take some precautions:
If you inhale the chemical, move to a place you can get fresh air. However, call your doctor if you experience breathing difficulty. If it comes in contact with your eyes, flush your eyes with water for about 15 minutes. Any contact with the skin, wash it off with a good amount of water. If you experience any irritation after use, then see a physician.
Hydrogen peroxide is incompatible with hot tub sanitizers:
As earlier stated, hydrogen peroxide is one chemical that can’t be sustained in a hot tub for a long time. One might want to use it with other good hot tub sanitizers like bromine or chloride. But hydrogen peroxide isn’t compatible with them. If they are used together, hydrogen peroxide will neutralizer them and of course, the whole essence of using the good sanitizers will be defeated.
Once the bromine or chloride is neutralized the hot tub will be exposed once more to micro-organisms which will still make the hot tub unhealthy for the users as well as damaging the components of the hot tub

What is a good alternative for hydrogen peroxide?
The good alternative is bromine. This is the most popular of all sanitizers for hot tubs. It is very effective and one outstanding thing about it is the fact that it comes in tablet form. Unlike hydrogen peroxide that evaporates quickly, when the bromine tablet is placed in the feeder, it dissolves slowly and can last long. Other good features of bromine that make it a better alternative to hydrogen peroxide include:
- Bromine is a certified sanitizer
First and foremost, bromine is primarily a sanitizer and has been certified to be one, unlike hydrogen peroxide that is mainly known as a chemical for dressing both wounds and cuts. PMRA has not recorded or registered any hydrogen peroxide-based product as a hot tub sanitizer. This shows that hydrogen peroxide is not recognized as a sanitizer and shouldn’t perform the role of a sanitizer.
- Bromine has a lower pH
With bromine, the pH will not be affected like when you use hydrogen peroxide. This simply means that your overall water chemistry in your hot tub will be more balanced when you use bromine.
- Bromine is more stable
Unlike the unstable nature of hydrogen peroxide which evaporates easily, bromine dissolves slowly. This makes it more effective than hydrogen peroxide. So bromine is more reliable and consistent as a hot tub sanitizer.
- Bromine is more effective
When it comes to the whole essence of tackling bacteria and other orgasms in the hot tub, bromine does a far better job than hydrogen peroxide. Hydrogen peroxide evaporates very fast, especially when exposed to sunlight. Bromine still works great, even with a high temperature of 75°F. Bromine remains stable and kills microbes at the temperature.
- Bromine is mild on the skin
This is another outstanding thing about bromine. It is gentler on the skin than hydrogen peroxide. Hydrogen peroxide is very harsh to the body. If it is not carefully handled, it can burn the skin and increase discomfort. It even gets worse for those with sensitive skin because it brings them more irritation and itches which can cause hot tub rash
- Bromine is a better choice for those with upper respiratory difficulties
Hydrogen peroxide is harsher on the lungs and can damage them. Those with respiratory issues will need to keep away from it. The properties of hydrogen peroxide are very hazardous that inhaling it will burn lung tissues. It makes breathing more difficult. So bromine that is milder is a better option.
Conclusion
Though hydrogen peroxide has disinfection properties, it is more of a strong oxidizer. It is not suitable for regular use or for treating the water in your hot tub. The truth remains that the hot tub needs more stable sanitizers that will be present in the water for a long time.
Because of the unstable nature of hydrogen peroxide, bacteria and other micro-organisms grow rapidly in the hot tub. This in turn makes the hot tub unfit for use.
And again, it is more hazardous than other chemicals that are used as sanitizers in hot tubs. Extreme care is needed with the use of hydrogen peroxide. The best thing to do is to avoid the use of hydrogen peroxide in your hot tubs.