Are Hot Tub Ozonators Worth It?

I like to avoid using chemicals as much as I can. So, with numerous chemical-free options out there on the market to sanitize spa water, are ozonators a good choice?

An ozonator is an excellent addition to a hot tub for its natural ability to sanitize spa water using ozone. Ozone generators cost around $150, making them an inexpensive sanitizer. They last for many years and are also economical to run. Most modern hot tubs are ozone-ready and ozonators are easy to install.

In this article, I’m going to show you

  • How ozonators work
  • Whether chemicals are necessary
  • Which type of ozonator you should buy

What does an ozonator do for a hot tub?

Looking around online, you’ll find a lot of technical jargon on ozonators that only leaves you more confused. So here is my simple explanation in plain English.

Ozonators produce ozone in a safe and controlled manner that aids a hot tub’s sanitizing system. The ozone sanitizes the water by replicating the natural oxidation process found in nature, destroying 99.9% of bacteria and viruses. They also break down other biodegradable materials to keep the water clean and pure.

Ozonators, or ozone generators, produce ozone by splitting apart the two atoms found in oxygen (o2) to produce single atoms.

Because the single atoms (O) are unstable, they seek stability by attaching themselves to oxygen molecules (o2) in the air, forming ozone (o3).

There are two types of ozone generators. Both perform the same function, but they go about it in different ways. Your personal situation will determine which type you must buy, but I’ll get on to that later.

Once ozone is generated, the gas is “injected” into the water, reacting with all the nasty stuff that lurks inside your hot tub, such as mold, bacteria, and viruses.

It also attaches itself to contaminants that find their way into the water from your body or from outside dirt and debris.

The ozone is able to deal with bodily fluids like oils, urine, and saliva, as well as personal care products such as deodorant, soap, makeup, perfume, sunscreen, hairspray, and gels.

By way of oxidation, the ozone breaks down all the organic and inorganic materials into less complex and less harmful molecules by rupturing the organism cell wall.

Ozonators also cause dissolved solids such as metals, minerals, and other contaminants to clump together (micro-flocculate) so that they can be removed by the hot tub filter.

Do you need chemicals with an ozonator?

If you’re seeking an alternative sanitizer, it’s likely that you want to reduce the number of chemicals in your hot tub. So do you need chlorine with an ozonator?

A hot tub ozonator needs to be used with chemicals such as chlorine or bromine. Ozone generators work alongside sanitizing chemicals by breaking up the chlorine or bromine molecules bonded to contaminants, reducing the number of chemicals needed by up to 50%.

When using an ozone generator, the good news is that the level of sanitizer will be much lower:

With ozonatorWithout ozonator
Chlorine0.5 ppm1 – 3 ppm
Bromine1 ppm3 – 5 ppm
The difference in parts per million (ppm) of chlorine and bromine with and without an ozonator

Being able to lower the amount of chlorine is excellent for those who suffer from sensitive skin. Better still is to combine an ozonator with bromine as you’ll find the water is a lot gentler on your skin and hair.

Whether you choose to use chlorine or bromine to sanitize your hot tub, you will still need to use an oxidizer to shock your spa water, but less often. It’s also possible to use non-chlorine shockOpens in a new tab. with an ozone generator.

If you’re looking to use your hot tub with zero sanitizing chemicals, I recommend pairing an ozonator with the Nature2 mineral purifier and Cense.

Balancing pH and alkalinity

No matter which type of sanitizer you use, spa water becomes unbalanced over time as people introduce contaminants to the hot tub from the outside world.

Remember that an ozone generator’s function is to sanitize the water, but adjusting the pH and alkalinity levels is still necessary to keep the water balanced.

Ozone is pH neutral, so it won’t adversely affect the pH of your hot tub water; however, you will still need to treat the pH with increaser or decreaser.

You’ll also need chemicals to treat the alkalinity and, depending on where you live, the calcium hardness to keep the water in check.

I recommend this chemical balancing bundle kitOpens in a new tab. as it has everything you need and saves you money and time by not having to buy each one individually.

Are hot tub ozonators safe?

If you paid attention at school, you’ll know that ozone can be harmful to health, causing damage to the lungs when inhaled. So are ozonators safe to use?

Hot tub ozonators are perfectly safe. Any excess ozone molecules that break free quickly convert back to oxygen, meaning that there are no harmful by-products. The ozone that is dissolved into the water has no adverse effects on human health and doesn’t contribute to air pollution.

Besides, the amount of ozone that ozonators produce is insignificant compared to the normal atmosphere in which we live.

Ozonators naturally sanitize, oxidize, and purify. This natural way of sanitizing the water is ideal if you’re looking to reduce the amount of chemicals you use in your spa.

How long does a hot tub ozonator last?

Sanitizers like chlorine are cheap to buy, so it’s important to recoup on your investment when purchasing an alternative sanitizing system.

The length of time a hot tub ozonator lasts is dependant on whether it’s a UV light or corona discharge model. UV light ozone generators typically last 3 – 5 years. Corona discharge chip ozonators usually last 1.5 years and corona discharge electrode models last between 3 – 5 years.

With a UV ozonator, it can be difficult to know whether it’s still creating ozone as the bulb continues to light up for many years, giving the impression that there is ozone.

However, just because the bulb is glowing doesn’t mean it’s generating enough ozone to sanitize the water.

Signs that it’s time to replace your ozone generator are:

  • When it becomes to difficult to balance the water
  • When the water smells bad
  • When your ozonator has exceeded its expected lifespan

It’s common for people not to know what type of ozone generator they have, so make sure to find out when you make the purchase.

To make things easier, I’m going to recommend my two favorite models: one for those that need UV, and one for those that require CD.

What is the best ozone generator for a hot tub?

While both perform the same function, ultraviolet light (UV) and corona discharge (CD) ozonators each have their own pros and cons. The type you need will depend on your personal circumstances.

Ultraviolet light ozonators

Ultraviolet lamps have been used for many decades to generate ozone. UV ozonators produce ozone as air passes over a UV lamp emitting a narrow band of UV light.

Standard UV ozonators are the less expensive option of the two and aren’t affected by humidity, making them the necessary choice if you live in an area with high humidity.

I recommend this UltraPure modelOpens in a new tab. for its powerful ozone output that outlasts pretty much all other ozonators on the market.

UV systems don’t require oxygen air dryers or concentrators to generate consistent and clean ozone, ensuring a more predictable water quality.

However, they require oxygen to be exposed to UV light for a longer period of time, making them less effective in larger hot tubs.

Corona discharge ozonators

Corona discharge generators are far more sophisticated than UV ozonators, and the technology involved to generate ozone can vary somewhat.

Essentially, CD ozonators generate ozone by running oxygen through an electrical field, which “injects” the gaseous ozone into the water using negative pressure or a vacuum.

The model I always recommend is one from DEL OzoneOpens in a new tab.. It’s energy-efficient and produces a lot less heat when compared to UV systems.

CD ozone generators have a longer working life. Because they don’t have cartridges or bulbs to replace, their plate ionizers may last up to 10 years.

However, because the gas that feeds the ozone generator must be very dry -80°F (-62°C), CD generators are not suitable for those living in humid areas (60% or higher).

The presence of moisture has an adverse effect on ozone production, leading to the formation of nitric acid. Nitric acid will cause corrosion in the internals of a CD ozonator, causing premature failure.

Joshua Milton

Joshua Milton is a seasoned hot tub enthusiast. With many years of experience in the industry, he offers valuable insights on hot tub maintenance, health benefits, and relaxation techniques.

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