What Is a Spa Ozone Generator? Are They Worth It?

What Is a Spa Ozone Generator - are spa ozone generators worth it

If you own a spa or a hot tub then you have probably heard or read about a spa ozone generator(sometimes called a hot tub ozonator) at some point. They are becoming increasingly popular in recent years and many people turn to them as a cheap, yet effective tool to solve the common problem of bacteria and chemical buildup in spas and hot tubs. So, what is a spa ozone generator?

In short, a spa ozone generator is a water purifying device, which is used to increase or just maintain the quality of your spa and hot tub water. It achieves this water purifying result by producing and injecting ozone into the water. Ozone helps reduce water impurities and is a good substitute for chemicals that are otherwise used to achieve the same result. By using a spa ozone generator you can save quite a bit of your time, your money, and any extra frustrations that might come with impure water. Spa ozone generators work best together with sanitizers to deliver optimal results.

Stick around to learn other important aspects of a spa ozone generator, such as how it works, pros & cons, how to install a hot tube ozonator, and if it makes sense to even have one.

How does a spa ozone generator work

Now that we know how a spa ozone generator actually works, the next logical question is “how”. Although it might seem quite complicated, the basic process is really simple to understand. Ozone generators take an oxygen molecule (O2), converge it with another molecule to turn it into ozone (O3 – three parts oxygen). This ozone (O3) molecule enters the water, lives there a short time and then that third molecule splits off and attacks whatever is in its path (in this case bacteria and other microorganisms). Repeat this process a few times and you get fresh, clean water.

Here you have a visual example of how this process actually looks like.

universal ozone system for spas

Source: SpaDepot.com

There are two main ways of how an ozone generator can make ozone – Ultraviolet (UV) light or Corona discharge (CD).

UV light ozonators, as the name already suggests, use ultraviolet light for their ozone creation process, which is similar to how ozone is produced in nature (via lightning strikes). It uses a process called photolysis of an oxygen molecule in order to create ozone. You have to get a new UV light ozone generator bulb every 2-3 years if you want to maintain their high effectiveness. Here are the pros and cons of a UV light ozone generators.

[i2pc pros_icon=”icon icon-thumbs-s-up” cons_icon=”icon icon-thumbs-s-down” show_title=”true” title=”UV Light Ozone Generator Pros & Cons” show_button=”false” pros_title=”Pros” cons_title=”Cons” ][i2pros]Effective at dealing with bacteria
Not affected by humidity levels
Low maintenance, easy to clean[/i2pros][i2cons]Shorter lifespan
Cost of running increases with hot tub/spa size
Reduces effectiveness over time[/i2cons][/i2pc]

Corona discharge (CD) ozone generators use plasma and electricity to create ozone. A long explanation of this ozone-generating process can be found here. If I summarize this process in short – an electrical discharge splits oxygen molecules into oxygen radicals (O) which then attach themselves onto other oxygen molecules (O2), forming ozone (O + O2= O3). Corona discharge ozone generators are the most popular and latest technology-wise. Here are their pros and cons.

[i2pc pros_icon=”icon icon-thumbs-s-up” cons_icon=”icon icon-thumbs-s-down” show_title=”true” title=”Corona Discharge Ozone Generator Pros & Cons” show_button=”false” pros_title=”Pros” cons_title=”Cons” ][i2pros]More effective at large volumes of water than UV ozonators
High life expectancy (10 years)
Very cost-efficient
[/i2pros][i2cons]Limited effectiveness in places with high humidity (over 60%)[/i2cons][/i2pc]

As you can probably tell from the comparison of pros & cons for both models, Corona discharge ozone generators are quite a bit more popular among spa and hot tub owners.

Benefits of using a spa ozone generator

So far we have looked at the two different groups of ozone generators and their pros & cons. But what are the benefits of using a spa or hot tub ozone generator over other water cleaning solutions in the first place? Here are the advantages:

Cost-effective. Most spa ozone generators will cost you only around $120 dollars, which is pretty much the total expense you can expect. This is very cheap for what you get in return, especially if you compare it with chemical sanitizers. UV ozonators have some maintenance cost involved with them (in the form of a UV light bulb replacement) every 2-3 years. Corona discharge ozonators do not have extra associated costs. Spa ozone generators will generally last you up to 10 years (3 years for UV light), which is a lot for such a small financial investment!

Natural solution to water purifying. What I mean by this is that you can find ozone in nature already. Due to its oxidizing properties, it is a very strong antibacterial water disinfectant. It is much more skin-friendly than chemical sanitizers (which can give you quite a few skin irritations!). There is also a big smell difference. Chemical sanitizers have that distinct, strong chemical smell (usually chlorine). Ozone, on the other hand, has practically no bad smells.

A more long-term cleaning effect. When you use chemicals to clean your spa or hot tub, you can expect to change the water every 3-4 months. Ozone generators prolong this water changing frequency by a factor of almost 3. So by using an ozone generator in your hot tub or spa, you need to change the water only once per year. That saves you quite a bit of time, water, and money!


Next, we are going to take a look at the possible downsides of a spa ozone generator. These are:

Adverse health effects of ozone. I have written quite a bit on this topic throughout my other posts. In essence, ozone can cause some respiratory issues in humans. This depends mostly on the amount of ozone that you are in direct contact with. The higher the amount of ozone, the more severe respiratory issues you can experience. This can range from small lung irritations to full asthma attacks. Therefore it is very important to wait a bit after using an ozone generator before jumping into the hot tub. If you are sitting in the water and can smell ozone, it means that not enough time has passed for ozone to dissolve completely. Ozone can also damage your hot tub cover, so make sure to remove it for at least a couple of hours every few days!

Installation issues. While installing a hot tub ozonator is not that hard, it can be quite easy to make a mistake. If you install it improperly, you can expect the water purifying effectiveness to go down as well.

How to install a spa or hot tub ozone generator

Most spas and hot tubs these days either already come with an ozone generator, or have space designed specifically for one. They are not very hard to install, but you do have to pay attention to detail and make sure you do it properly. Otherwise, your water purifying performance will suffer as a result. Here are the general steps that you can use for orientation:

  1. Place the ozone generator near the spa cabinet
  2. Install the check valve
  3. Connect the check valve to your spa
  4. (optional) Configure the ozone tubing into a Hartford loop
  5. Either plug the ozone generator or hardwire it to your system
  6. Configure the automatic timers for duration

This is just a basic outline of the steps for installing a hot tub ozonator. You can refer to the video below for a better demonstration.

Source: youtube/leisure time inc

Keep in mind – if this still looks too complicated to you, no worries. You can always hire a professional to install a spa ozone generator for you. Prices vary a bit, but you can expect to spend around $100 for this service.

Are spa ozonators worth it?

By now you have learned what a spa ozone generator is – a water cleaning and purifying device that uses ozone to remove organic and inorganic contaminants in your hot tub or spa. After going through the different models of ozone generators and their pros & cons, the final question remains – are spa ozonators worth it?

Yes, considering everything we wrote so far – a hot tub ozonator is worth it for most spa or hot tub owners. For a price of around $100 you get a device that will last you years, purify your water better than chlorine or other chemicals, save you time, money, and a lot of potential headaches. I personally believe that the pluses here outweigh the few downsides which come with ozone generators.

In most cases, I would recommend an ozone generator that uses corona discharge over a UV light ozone generator. This is because corona discharge is more cost-effective, lasts up to 3x longer, has lower maintenance, and is more effective at cleaning a larger amount of water. The only situation where I would recommend a UV light ozone generator over a corona discharge one is if your spa or tub is located in an environment with high humidity levels (over 60%). Everything else – corona discharge all the way!

A final note: even tho ozone generators are definitely worth it, you still want to combine them with at least a small amount of chemical sanitizers. This will give you the most optimal cleaning result. Is an ozone generator alone enough to keep the water clean? Yes. Is it as good as combined with chlorine or bromine? No. You need at least a small amount of chlorine or bromine for the purpose of residual sanitization. This is just a fancy way of saying that you need to keep your water clean between ozone cleaning cycles.

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The author is an Air purifier expert with overall knowledge of air and ionizers.