Maintain a Hot Tub Without Chemicals: Natural Alternatives

Michael Keenan


Hot Tub Water Chemistry

Are you looking for a way to maintain your hot tub without using harsh chemicals? You’re not alone. More and more people are searching for natural alternatives that can keep their hot tubs clean and sanitized, while avoiding skin irritation and eye strain.

In this article, I’ll cover several methods of maintaining a chemical-free hot tub so you can enjoy a relaxing soak without the worry of added toxins. From salt-based systems to UV lights, we’ll explore the different ways to keep your water clean and reduce the need for harmful chemicals.

While most methods require some type of chemical use, there are several systems that can help to reduce the use of harmful chemicals. I’ll also share some special tips on how to prolong the life of your hot tub! Relax and read on!

how to maintain a hot tub without chemicals

Quick Answer:

Enjoy your hot tub the natural way! With the right knowledge and tools, you can maintain a hot tub without using harsh chemicals like chlorine or bromine. There are several alternatives you can try.

These include UV lights, enzyme-based treatments, mineral ionization, salt-based systems, non-chlorine shock and ozonators that are effective in keeping the water clean and clear.

Regular draining of the tub, cleaning of filters frequently and maintaining a proper pH balance also help reduce chemical use.

Natural Hot Tub Treatment Alternatives

There are several natural treatment alternatives that you can use for your hot tub. These can help to reduce the amount of chlorine used or the use of any other chemical sanitizers to keep it clean.

UV (Ultraviolet) Lights

Using ultraviolet lights is a great way to sanitize your hot tub without using chemicals like chlorine. The UV system works by deactivating the viruses and bacteria in the water through radiation when the water is passed through a filtration system and a tube containing UV lights.

While UV treatment helps to remove contaminants from the water, it is not a standalone solution and you may need to shock the water to maintain the clarity of the water.

Enzyme-Based Treatment

Enzyme-based treatment is a good natural alternative to treat your hot tub water. Usually, these products are food grade and help to digest the human skin fragments, body oils and other organic wastes that can be a breeding ground for pathogens and germs.

It also prevents the filter of the tub from getting clogged and the build-up of unpleasant foul odors.

While you may still need to use shock and sanitize to effectively clean the hot tub, enzyme-based treatment can help to reduce the ammount of chemicals needed to maintain the water.

Mineral Sanitizers – Ionization

This process makes use of copper and silver ions to keep the hot tub water clean. When the minerals are ionized by the water, they form ions that are positively charged that are released into the water.

The ions are ingested by the pathogens in the water and are either killed, sensitized or made weaker so that they can be destroyed by other methods.

While mineral ionization helps to control the bacteria and algae, it does not work effectively on its own and you may need to use some other oxidizer like chlorine or bromine granules to treat the other contaminants and sanitize the water effectively.

salt based systems

Salt-Based Systems

Salt-based systems do not make use of chlorine and bromine; however, the process is not completely chlorine-free. In the end, the electrolyzing process of the salt does produce chlorine.

So, your goal of maintaining a completely environmentally friendly hot tub without using chemicals may not be met. They do reduce the ammount of chemicals used significantly but can’t be truly chemical free. See my guide on how to convert your hot tub to a saltwater system for more details.


Ozone is an excellent oxidizer, as well as a sanitizer that helps to break down the organic contaminants in your hot tub and also eliminates most of the bacteria present in the water.

Ozone is produced by an ozonator when electricity discharge passes through the air or when UV light is shone in the air.

The process produces some stable oxygen, which then reacts with the electric discharge or UV light and produces ozone, which is less stable than oxygen. The ozone-enriched air is then passed into the hot tub and helps to oxidize the bacteria, as well as other contaminants, thus sanitizing the water.

Corona discharge ozonators generate more ozone; however, they do not tolerate high humidity. The air must be dried to ensure that the ozonator works properly, which makes these types of ozonators quite expensive.

UV-type ozonators are most commonly used for hot tubs in homes.

However, ozone disperses very quickly and there is no way to keep a reserve of the ozone. Also, there is no way to measure the amount of ozone produced.

Ozone may not be effective against some types of bacteria and pathogens and you may still require to use some chlorine or bromine, although in very small quantities.

Non-Chlorine Shock

Shocking your hot tub essentially is the process by which the organic compounds present in the water responsible for unpleasant odors and causing the water to become cloudy are broken down.

Shocking helps to oxidize the contaminants in the water and releases them in the form of a gas, eliminating the pathogens and algae, reducing the need for chemicals and also helping to enhance the life of the equipment.

It is recommended to shock your hot tub once in 7 to 10 days to keep the water clean; however, the frequency may depend on your size of the hot tub, hot tub usage, type of water, the weather in the area you live in, humidity levels and other factors.

There are 2 types of shock treatments commonly used – non-chlorine shock and dichlor shock.

  • Non-Chlorine Shock: This makes use of MPS (monopersulfate), an oxygen-based shock for regular maintenance of the hot tub.
  • Dichlor Shock: This uses sodium dichlor, which is a form of chlorine, which acts as a shock, as well as a sanitizer. A dichlor shock is usually recommended when the hot tub is refilled, after which it is best to go with the non-chlorine shock option.

Remember that with most shock treatments you need to wait before using the tub. See my article for wait times and why they matter. And, please don’t over shock your spa – it can cause problems.

Tips to Keep Your Hot Tub Water Clean without Chemicals

Here are some tips on how you can keep the water in your hot tub clean without using chemicals or by reducing their use.

Drain the Hot Tub Often

It is recommended that you drain your hot tub once every 4 to 6 months and if you’re not using any chlorine, then you must drain the water more often, i.e., every 2 to 3 months. See my article on how often you should change your water for more details.

When draining the hot tub, make sure that you use a product that helps to remove build-up in the pipes, jets, hoses or other crevices of the hot tub.

Clean the Water Filters Frequently

To ensure that the water filters in your hot tub work efficiently, make sure to clean them regularly. You can do this by making use of chemicals and brushes specially designed to clean the filters.

Alternatively, you can simply run the filters under a cold-water faucet or put them into the dishwasher without a detergent.

Depending on the size of the hot tub and frequency of use, it is a good idea to replace the water filters frequently.

If you are treating your hot tub using a chlorine or bromine treatment, then the filters can be replaced once in 1 or 2 years; however, if the hot tub is a chlorine-free one, then it is recommended that you change the filter more frequently, every 6 to 12 months.

running the pump longer

Run the Pump Longer

Typically, a hot tub has a pump that helps to circulate the hot water and sanitizer, which prevents the water from stagnating and becoming a breeding ground for bacteria, mosquitoes, algae, etc.

So, it is very important to run the pump of the hot tub for 8 hours at least or according to the manufacturer’s instructions. Keeping the water circulating can also help to reduce the number of chemicals needed to maintain the water.

Always Shower before Getting In

You must always have a shower with water and soap every time before getting into your hot tub. This helps to reduce the body oils, make-up, hair products and other personal products getting into the water and dirtying it.

This is an effective way to reduce the use of chemicals and the amount of sanitizer needed to keep the hot tub clean.

showering before hot tub

Keep Your Hot Tub Covered

To keep your hot tub clean and well maintained, it is a good idea to keep it covered when it is not in use. This will help to prevent insects, dust, dirt and debris from getting into the water.

Covering the hot tub also helps to prolong the effectiveness of the sanitizer and reduces the chemicals required to maintain the water. This is especially important if you have a chemical-free hot tub.

Maintain the Right pH Balance

Irrespective of the sanitation method you’re using for your hot tub, it is very important to maintain the hardness of the water and the pH level of the water at the appropriate levels because if the levels are not right, this will reduce the effectiveness of the sanitizers in keeping the water clean.

The recommended pH levels are between 7.2 and 7.5, the hardness of the water must be between 180 ppm to 220 ppm and the alkalinity around 80 ppm to 120 ppm.

Test the water in your hot tub using reagents or test strips twice a week at least and add the chemicals required to keep the water balanced.


What are the benefits of maintaining a hot tub without chemicals?

The benefits of maintaining a hot tub without chemicals include cost savings, less skin irritation, and reduced environmental impact.

How often should a hot tub without chemicals be cleaned?

A hot tub without chemicals should be cleaned every two weeks or so to ensure the water stays healthy for users.

How can I prevent bacteria from growing in my hot tub without using chemicals?

Proper filtration of the water is key to preventing bacteria from growing in your hot tub without using chemicals. This can be done by installing an effective filtration system that removes dirt and debris from the water on a regular basis.

Parting Thoughts

To maintain a hot tub without chemicals is possible and can be beneficial for your skin, the environment, and your wallet.

This article discussed several options to explore including UV lights, enzyme-based treatment, mineral ionization, salt-based systems, and ozone. I also shared some tips on how to keep a (nearly) chemical-free hot tub clean such as draining the tub often and maintaining the right pH balance.

Although it may not be possible to eliminate all chemical use in hot tubs, in every situation, I strongly believe that most of us can easily reduce the amount of chemicals we use in our tubs.

There are plenty of other natural alternatives that are effective, while helping to reduce the use of chemicals significantly. Sometimes it just means a little more effort but it can reduce costs – financially and to the environment!

I hope that after reading this article, you’re able to find the best way to maintain your hot tub without the use of chemicals – or at least reduce your use significantly.

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!