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  • Writer's pictureAqua Warehouse

How Long Will a Hot Tub Last Without Chemicals?

Updated: Jan 12, 2023

Do you love spending time in a hot tub but want to relax in an eco-friendly way? Then, consider using a chemical-free tub, as it will benefit you and your surroundings. These hot tubs do not contain harsh chemicals or compromise your hot tub experience.

But you might ask - how long can you run a hot tub without chemicals? Your hot tub can last a surprisingly long time if left untreated. You can follow some essential techniques to run your spa without hot tub chemicals. We'll look at most of them in this article.

Can you run & use a hot tub without chemicals?

Yes, you can run and use a hot tub without chemicals. There are several ways to do this, such as using natural products like vinegar and borax, using ozone or ultraviolet light technology, or using electrolysis systems.

Some of these methods require more frequent maintenance than others but all are viable options for keeping your hot tub clean and free from toxic chemicals. However, it is important to keep in mind that these methods may not be as effective at eliminating bacteria and viruses, so it is essential to ensure the water is regularly tested and treated when necessary.

Additionally, it is a good idea to shock the hot tub after each use to help prevent any build-up of organic materials that can cause bacteria and algae to grow.

You might want to run your hot tub without chlorine and bromine due to sensitive skin or other reasons. You should know that it is possible, but running a hot tub like this will require special attention and maintenance.

Can you go in a hot tub without chlorine?

Some people might no longer want to use chlorine because of a terrible experience in a public pool or elsewhere. But that doesn't mean chlorine is bad for your spa.

Chlorine is one chemical that sanitises your hot tub with maximum efficiency. Since sanitising chemicals like chlorine are tasked with attacking organic materials, it helps get rid of algae, bacteria, viruses, germs, and other contaminants. While bromine works more effectively at higher temperatures, chlorine is still less expensive.

What are the dangers of getting in a hot tub without chemicals?

Without adding chemicals to your hot tub and consciously maintaining it, it could pose the following dangers:

  • A hot tub without chemicals is the breeding ground for certain bacteria, fungi, and algae.

  • Your hot tub might get filled with unwanted germs and turn green and cloudy.

  • Different temperatures could cause optimal growth for bacteria, which could be detrimental to your health, causing infection or irritation.

Do you damage hot tub components if you don’t add chemicals?

There are cases where you could damage some hot tub parts if you don't use chemicals. Without hot tub chemicals, your water can become cloudy or green. There could also be undissolved particles. These can corrode your tub/spa components.

How long can you leave water in a hot tub without chemicals?

If you don't want to use chemicals in your tub/spa water, always ensure you drain it and refill following every soak.

You should change the water weekly if the spa is in moderate use. If you don't use the spa at all and use a surface tub cover, you can wait a month before changing the water, as that would be when the water is unsafe.

How long does it take for bacteria to start growing in a hot tub without chemicals?

Due to frequent use by bathers, bacteria can start growing in the spa in the space of 2 to 3 days. Different factors could either slow down or speed up this process.

What are the food sources for bacteria in the hot tub?

Some sources that cause bacteria and other microorganisms to grow in your hot tub include urine residue, germs, sweat, dirt, and body oil.

Practical tips for running a hot tub without chemicals or reducing them

You can have a chemical-free hot tub. Many hot tub owners prefer not to add chemicals, but they feel this could impact the cleanliness of the water.

These are the best tips to ensure you run your hot tub with few or no chemicals.

Get a hot tub cover

The best way to keep your hot tub clean and control bacteria without chemicals is to invest in an inexpensive hot tub cover. Keeping the hot tub covered when it is not in use is advised as an effective way to prevent contaminants from getting into it. If the tub is outside and the surrounding environment is a bit messy, a cover is a must.

Shower before use

Taking a shower or bathing before using hot tubs avoids contaminants like dead skin cells, body oils, shampoo, conditioner, and lotions interfering with the water chemistry and causing poor alkalinity. Your hot tub is not meant to wash off dirt from your body, so make sure you are clean before you get into the tub/spa.

Maintain proper water balance

Most hot tubs need premium-quality water to ensure an effective soak. If you are thinking of running an inflatable hot tub or another kind, try to keep the pH levels in the 7 to 8 range.

You should also ensure that no external factors affect the fresh water, like sunlight, as it could impact the pH levels and make the tub susceptible to corrosion. Keep the water balanced at all times.

Use only the most important chemicals

Hot tub users that want to run a chlorine-free hot tub need to know that you should not put more than required for your hot tub. Fewer chemicals would still be great for your spa water, as killing bacteria should be your primary aim.

Drain more frequently

Draining hot tubs and frequent water changes make tubs easier to disinfect and clean. Generally speaking, if you put the right chemicals in the correct amount, they will still be very effective if you frequently change the water.

Clean & maintain the filter

Ensure you keep your hot tub filters clean, as a clean filter is a crucial step in proper maintenance. When cleaning the filter, soak it in a tub with a capful of bleach mixed with hot water. Rinse it out, then leave it to dry for one day before reinstalling it. This will help you save money in the long run as you will keep dirt buildup at a minimum.

Check our guide to learn more about cleaning your hot tub filter.

Utilize an Ozonator or UV filter

Typically, ozone systems will greatly reduce how much disinfectant you need for your hot tub water. While an Ozonator cannot fully eliminate the need for chemicals, it will drastically lower the chemical levels. UV filters also reduce the amount of chlorine needed as they use UV light to sanitise the water.

Remove biofilm buildup

Soaking in a hot tub with a high level of biofilm can be extremely dangerous, which is why removal is beneficial and vital to keep the water safe. Make sure you use a biofilm removal product frequently to ensure the safety of hot tub water.

Run the pump longer

If there is more debris than usual inside your tub/spa, leave the pump running for an additional minute or two before you turn it off. This will help keep your water clean and free of debris.

Do you need to add hot tub chemicals to self-cleaning hot tubs?

No, manufacturers of self-cleaning hot tubs typically design them to require fewer chemicals than a traditional hot tub. They are designed to automatically monitor and adjust chlorine levels and other sanitising agents as needed. The use of additional chemicals is usually not necessary. But it may depend on your particular model or brand of hot tub. Follow the manufacturer's instructions for your specific product.

What are the best natural alternatives to hot tub chemicals and chlorine?

These are some of the best alternatives if you don't want to use hot tub chemicals.

Ultraviolet (UV) system

Whether you have inflatable hot tubs or traditional ones, you can use a UV system to replace and do the work of chlorine. It maintains your hot tub water sanitary through UV radiation as the water moves past the UV bulbs. However, you might have to invest in shock treatments to improve water clarity.

Salt-based systems

The salt system eliminates the need for bromine or chlorine. But remember that salt systems do not lead to a non-chlorine hot tub. This is because when the salts go through the electrolyzing process, it creates chlorine.


The ozone system injects ozone into your water. It's a great system if you don't want to use additional chemicals. Some hot tubs might need adjustment to accommodate an Ozonator.


Ionizers inhibit bacteria and algae by releasing ions into your spa water. While they can be used as natural hot tub water treatment, you should note that they do not sanitise. You might still need to include a sanitiser in your budget. But they do lower the quantity of sanitiser needed.


If you want to run your hot tub without chemicals, consider using polyhexamethylene biguanide, as it is a viable alternative. It is a subtle sanitiser that still requires the need for non-chlorine and non-bromine-based shock. Since biguanides do not mix with chlorine, you will need to go through some processes to convert your hot tub back to bromine or chlorine if you change your mind later.

Non-chlorine shock

Non-chlorine shock (usually in tablet form) is not a sanitiser, unlike bromine or chlorine shock. That said, it doesn't ideally need to be a non-chlorine hot tub. Non-chlorine shock treatments are known to improve water clarity, eliminate contaminants, and also oxidize the water. Using this treatment in a bromine spa activates and bolsters the bromine levels and creates "free chlorine" if your hot tub has chlorine sanitiser.

Enzyme-based treatment

The enzyme-based water treatment is also one of the natural alternatives. This process doesn't necessarily remove the need for shock and sanitiser. But it ensures you don't need so much of other chemicals to maintain clean hot tub water.


If you are looking to run your hot tub without chemicals, then you should keep in mind that you will need to follow a more diligent and rigid maintenance plan.

You can use your spa without hot tub chemicals, but you will have to monitor everything by yourself, like the water temperature, water hardness, pH level, water clarity, and even the chlorine levels (with test strips) if you decide to use some other alternatives.

A chemical-free hot tub has more benefits to the health and environment in addition to being cost-effective.


1. How long can hot tub water sit untreated?

You can skip water treatment for your hot tub for about 2 to 3 weeks before it would no longer be safe for you to soak in. No sanitizing chemicals means you putting yourself at risk of contamination.

2. Do I Have To Clean my Hot Tub More often If I don't add any chemicals and chlorine?

Chemicals and sanitisers like chlorine ensure that your water is clear and clean as well as perfect for relaxing. So, if you have a chlorine-free hot tub, you will need to drain and clean it out every 2 months. Also, ensure that you maintain strict hot tub maintenance so that you have properly clean warm water to relax in.




Jess Court

I'm Aqua Warehouse Groups Marketing Officer - overseeing all things news worthy in the hot tub industry, with tips and tricks that are bound to make a splash.

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