Ozone Generators for Spas

	Ozone Generators are very effective means of oxidizing spa wastes and organics byproducts.  However, ozone's presence in pool water quickly depletes and can benefit greatly from the presence of lower levels of chlorine or bromine or sanitizing metallic ions.  Click for Product and Ordering Information.

How to use an ozonator, to help sanitize a spa, swim spa or hot tub? Ozone (O3) is a form of oxygen (O2) and is a very strong oxidizing agent that can help control microorganisms, destroy organic contamination, unwanted byproducts, dead algae and organic debris. It is not a complete spa or hot tub sanitizer, in the truest sense, because ozone does not remain in water for long periods of time. In a spa or hot tub, there must be a backup sanitizer such as, chlorine or bromine, usually at about 1/2 the normal level. Because the ozonator does most of the oxidizing, an Ozonator, also known as an Ozone Generator, will reduce the quantity of the backup sanitizer required for proper sanitation. This is especially important in larger heavy bather usage situations. The devices that generate Ozone fall into two categories: UV or Corona discharge. Commercial spas and other high bather usage installations should utilize a unit, as it is sized to be capable of producing the greater quantities of ozone, that these situations require. With ozonation, the water chemistry should be maintained in the typical manner. If problems arise, refer to the Spa Problems Page, as a source of problem-solving information, broken down into various categories.  Scroll down the page and click on the linked keywords, catch phrases or images, in the archived answers below, to access additional information, on that topic or product.

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► What Is Ozone?

My wife and I have been looking at hot tubs. Some of them seem to come equipped with an ozone device or offer it as an option. How does this work? Is it worth getting?

M & L, Rutherford, CA, 3/29/2010

Ozone is a highly reactive form of oxygen. Ozone (O3) contains 3 atoms of oxygen. The oxygen (O2) we breathe contains 2 atoms. It is this third atom of oxygen that allows ozone to oxidize or destroy organic wastes and contamination, bacteria, algae, etc. in spa or hot tub water. It is effective, even at very low levels. The only limitation is that once produced it quickly leaves the water. If ozone is not continuously produced, there will be periods where there may be little sanitizer present. For this reason, in spas and hot tubs, ozone is used in conjunction with a backup sanitizer, such as chlorine, bromine, mineral sanitizers or ionization. In spas and hot tubs, ozone can be introduced in the water with the use of a device called an Ozone Generator or Ozonator. The use of ozone will not eliminate the need to add other chemicals or maintain proper water chemistry, but it will reduce the amount of chemicals required and should simplify maintenance. It's worth having! I hope that I have been helpful. Good luck with your choice.

Sincerely. Alan Schuster, 3/29/2010


► Ozone And Bromine In A Spa?

I am a new spa owner of 4 months. We have a spa with an ozonator and treat it with bromine. I run the ozonator about 4 hrs twice a day. I had problems with a rash using chlorine and find the bromine is also a problem, no one else in my family has any trouble. My question is I can not keep the bromine level down, we live in the northern states so it is covered a high percentage of the time now in winter. It can stay up around 10 plus on test strips after 15seconds. Is there anything that can be done to lower bromine levels?

Rick L., 12/15/2012

Ozone generators can do a very effective job of removing organic wastes and byproducts that would. otherwise, react with the bromine. While it necessary for ozonation to use a backup sanitizer, such as bromine, the amount required should be considerably less. You can instantly lower the bromine levels by adding a small amount, as per label directions, of a chlorine neutralizer. This product is only intended as a solution for an occasional overdose and not as part of routine treatment. Once the bromine level has been reduced - you will probably only need 1-3 PPM as opposed to 3.5 PPM - cut back on the amount of bromine being used. Inasmuch as you are the only one suffering from a rash, you might be sensitive to chlorine and bromine in the hot water application. You can reduce the chlorine and bromine levels dramatically, by supplementing the ozonator with a mineral sanitizer or ionization unit. This will provide the necessary backup sanitation, for those periods when ozone is not being produced or many not be available. Some mineral sanitizers cannot be used in water that contains bromides. Only THE FROG Mineral Sanitizer can be used in a spa that contains bromides or bromine.  I hope that this information will prove helpful. Enjoy the holidays.

Sincerely. Alan Schuster, 12/16/2012


► Getting Set Up?

Great web site Alan. I am in the process of setting up a spa (approx 450 gal). I will be installing an ozonator and probably using a mineral purifier. I would like to minimize bromine and chlorine, and minimize maintenance. Can you recommend a top of the line ozonator? Secondly, are there any other devices I can install that will automatically balance the water, so maintenance is reduced? Lastly, can you recommend which chemicals would be best suited, both type and brand. Thanks again.

Steven, 4/20/2011

UltraPure Water Quality has been manufacturing quality Ozone Generators for over 20 years.  The use of a mineral sanitizer will add a backup sanitizer and should help you to greatly reduce chlorine or bromine usage. The FROG Mineral Sanitizer is the only one suitable for use with bromine. In addition, this combination will minimize the frequency of pH and total alkalinity adjustments. Having the water tested and balanced, will get you off on the right foot. Thereafter, some periodic adjustments will have to be made, based upon the usage patterns of your spa and the nature of your source water. There is nothing that will automatically balance the water - at least nothing that you should get involved with. I hope that I have been of assistance. Thanks for visiting the website and enjoy the spa.

Sincerely. Alan Schuster, 4/21/2011

► Ozone Or No Ozone?

Hello, hopefully you might be able to help me. I have a question about Ozonators. I am buying a spa and it has been recommended that I do not need an ozonator, The dealer also mentioned with a 1 year old child that might be in the spa with us, it is not recommended. It seems everyone recommends getting one? I have a friend who told me he lowers the temp of his spa in the summer time and says he has to have an ozonator in order to keep it clean. I haven't read anything to support that theory. What are your thoughts, should I invest the extra $200 bucks or not. Thanks for any feed back.

Mike, 8/30/2008

This is almost a no brainer. I can't think of a reason for you not to put in an ozone purification system, aside from the fact that you don't want ozone being produced while the bathers, especially children, are using the spa. The ozonator should shut off, if the pump is switched to high speed. The ozonator will go a long way towards maintaining optimum water quality. It is worth the extra money and will pay for itself in terms of reduced chemical usage. I hope that I have been helpful.

Sincerely. Alan Schuster, 8/30/2008


► Drain And Fill?

Hello Alan! G. B. the dj here! The wife and I just traded one top of the line spa for another top of the line spa, And boy do we love it. We now have 500 gallons of beautiful city water in our new tub and it costs us 50 cents to fill'er up. For 4 years I struggled with water issues with bromine and biguanide; never really happy with our water clarity (OR LACK OF). Now for my question? Can I forget most of the chemical stuff and simply drain all or part of the water each week and not damage the spa or the wife? We use our tub 4 or 5 times a week and LOVE IT. Thanks, dude.

G. B., 1/24/2005

We certainly don't want to "damage" the wife! Most high end spas come with an ozone generator or should. Newer units probably have the ozonator on a separate low speed pump and this allows for better performance, as ozonation takes place throughout the day. Biguanide has a tendency to foam and this can interfere with the action of the ozonator. In addition, biguanide, after a period of time, can result in the formation of resistant microorganisms and lead to unsatisfactory conditions. Bromine and ozone usually work well together. Now for your question. The practice of "drain and fill" is only practical for jetted tubs that have a relatively small volume of water. Using your spa, in this manner, will turn the water into old bath water within a few days, at most. The conditions will get progressively worse and could "damage" yourself and the wife. I suggest that you go with an ozonator and either a mineral sanitizer and a low level of bromine. Test the water regularly and there should be few problems. I hope that I have been helpful and that you keep loving the spa.

Sincerely. Alan Schuster, 1/25/2005


► Knows What Works?

I just happened to run across your website and can't believe all the information you have. Great site! Thanks! 10 years ago, I bought a new hot tub (350 gal) and it was a horrible experience getting the water right. It was green, it was milky, just about everything others have described in their e-mails. I must have changed the water 3 times before I just stopped putting all those chemicals that the store got me to buy, $150.00 worth. My water is so clear, no foaming, just right. I have an ozonator and I have to assume it still works for the only thing I put in my water is a little shock once in a while and clean the filter. Well, I'm ready for a new one, one with more jets and I fear I will have the same experience I had 10 years ago. The hot tub manufacturer suggests I DON'T get an ozonator. I called the store this morning and requested one be installed anyway after reading all your problems folks have here on your site. When I explained to the store how old my tub is and how maintenance free it has been, they just said I was very lucky. Can you give me any advise on making the installation of my new hot tub a good experience? Thanks again and I have given so many people this website.

Gloria V., 6/6/2006

Yes. Have an ozone generator installed. Preferably one that uses a second pump and can run 24/7. That way all you should need is a periodic addition of chlorine or shock treatment. To be on the safe side, try and keep a free chlorine level of about 1 PPM. It should take very little chlorine because of the ozonator.  But, you already know this! You know what works for you, so why change? You might consider adding a mineral sanitizer. It only adds sanitizing ions and acts as a backup for the ozonator. Good luck and enjoy the new spa.

Sincerely. Alan Schuster, 6/6/2006


► How Much Is Enough?

Thanks for your awesome website! It's a great source of information. I recently started using a silver ion purifier with my hot tub ozonator. As per the manufacturer of the ion purifier, I've been adding shock with each use. However, I'm having some turbidity issues. My pH and alkalinity are within the recommended limits. Do you have any thoughts on this? In addition, how do I know that my ozonator is working? What is a typical ozone concentration in water that my ozonator should be maintaining in order to be effective? I'm considering purchasing a LaMotte test kit to monitor the ozone levels. Any information you can provide will be appreciated. Thanks.

Cathy, 3/18/2005

Ozone functions at very low levels and does not remain in the water for long periods of time. It is best to operate the ozonator for period throughout the day, instead of a single long run. I suggest 3 or 4, 2-hour sessions spaced apart. Mineral Sanitizers must be used with oxidizers or shock treatment. Ozonators do not necessarily have to be used with shock, although it is a good practice to add some at first signs of a loss of water quality or after heavy bather usage. When testing for ozone, make sure the unit is operating and sample near the return flow. Concentrations are low, just a few hundredths of a PPM. You might be able to smell it, when the cover is removed.  There is no ready explanation for your turbid water, other than inadequate oxidation or filtration. Try maintaining a low level of chlorine, about 1 PPM. With an ozonator functioning it should require little chlorine. If that is not the case, the ozonator might not be being used properly or outputting enough ozone. I hope that you will find the information helpful and thanks for your kind comments.

Sincerely. Alan Schuster, 3/18/2005


► Difference Of Opinion?

My wife and I recently purchased a spa. We have been thinking about adding a ozonator. Our spa only has one pump for filtering and jets. Would we be wasting our time buying a ozonator? We have heard so many different stories from different spa dealers. Some say that we wouldn't be gaining much without a separate circulating pump. I would like your comment on the subject. Thanks!
        
Curt H., 2/28/2005

It is true that many higher end spas have a separate low speed pump just for the ozonator. This allow ozone to producedthroughout the day. Since ozone doesn't remain in the water for extended periods of time, this is clearly the better way to ozonate. Not all spas are equipped with two pumps, but can still benefit from the improved water quality, an ozonator can produce. All that is required is for the timer to be set, so that the ozonator operates for 4 2-hour periods, spaced throughout the day. That way the spa is never more than a few hours from ozonation.  This is not something inflexible and individual requirements should allow for differences. But, the theory is the same: ozonate for periods spread out during the day and not in a single continuous run. In either case, a backup sanitizer, such as a mineral sanitizer, chlorine or bromine, should be employed. An ozonator will help enhance your spa experience and make water quality simpler and more consistent. Go for it and enjoy the spa.

Sincerely. Alan Schuster, 2/28/2005


► Sensitive To Spa Water?

I wrote to you earlier this year about a problem I am having with my spa. I will review the problem. Two years ago I installed a spa. My wife and I enjoyed its use almost very night for about three months. Then my wife started to get an itch that would not go away. She went to her doctor and then to a dermatologist. He said my wife had eczema and advised her to have a warm bath after using the hot tub and he prescribed some creams. My wife is 68 years old and has never had skin problems so I had some doubts about his findings. She continued to use the hot tub about once a week but the itchiness continued. So early this year I thought that I would change from bromine to chlorine and sought your advice on the change over. I have been using chlorine for about six months and there is no improvement in her condition. I still suspect that my wife is sensitive to some chemical in the hot tub. I substituted baking soda for the alkalinity control and now am wondering if it is the chemical causing the itchiness. Would you please comment on this? If you think it could be the problem, should I empty my spa and start with a store bought alkalinity agent? Thank you for your help.

Nelson D., Oberon, AR, 8/1/2004

I doubt that the baking soda is part of the problem. It is amongst the most innocuous of chemicals. Bromine contributes certain byproducts to the water and if you did not drain the spa before switching, I suggest that you do so at this time. Otherwise, even though you are adding chlorine, it is being converted to bromine. My best suggestion are that you get an Ozonator installed (unless the spa came with one already installed). This will allow you to use far less chemicals to maintain sanitation. In fact, you could use the Ozonator, in conjunction with an Ionizer or Mineral Sanitizer and be close to chlorine and bromine free.

Sincerely. Alan Schuster 8/2/2004


► Hydrogen Peroxide?

We have a hot tub and would like to use hydrogen peroxide instead of the normal chemicals. My husband is allergic to the chlorine and bromides. How much Hydrogen peroxide do we use and what %. We were told that it should be a 10% concentration but we can't find any hydrogen peroxide above 3%. I thought maybe you could help us. Also do we nee to use any kind of a shock at the first? Hope you can help!  Thanks.

Jo, 7/10/2005

I am not sure that using just hydrogen peroxide will provide adequate sanitation. In pools and spas, it is used as a shock treatment with biguanide. It is available in concentrated form in many pool and spa outlets that offer biguanide products. Have you considered the use of an ozone generator and a mineral sanitizer or ionizer. This combination would come close to being chlorine and bromine free. The ozonator could negate the need for hydrogen peroxide and a mineral sanitizer or ionizer would release metallic ions and act as a persistent sanitizer. Hydrogen peroxide can be used as a shock treatment and a mineral sanitizer or ionizer as the primary water sanitizer. However, in most cases better results are obtained, if you maintain a lower level of chlorine or bromine.  I hope that I've been helpful and given you some food for thought. Good luck with your decision.

Sincerely. Alan Schuster, 7/10/2005


► Retrofitting An Ozonator?

I purchased a house with an older spa that does not have an ozonator. Is it possible to add one, and how would I go about it? Thank you.

Jay S., 5/27/2004

An ozonator can be added to an existing spa. Most newer spas are equipped with one or have provisions for their addition, within the confines of the existing cabinetry. Older units may not be able to accommodate an ozonator within the enclosed cabinet and may require an external installation. In either case, a local spa professional should be able to help you determine your best options. It's a wise move.

Sincerely. Alan Schuster, 5/27/2004


► To Backup Or Not To Backup?

Alan, I appreciate your website and the info you present on spa maintenance. It has been most helpful to myself, a new spa owner  in Minnesota. My question is this: I have purchased a new spa with an advanced water management system that has a continual low speed circulating pump ozonator with no down time. In addition, I run the circulating pump of the spa 4 cycles a day for 1 hour. In reading your responses to questions regarding ozonators you are concerned with a back up sanitizer for down time. If my spa has no down time how important is a backup sanitizer such as mineral ionization? My other question-how necessary is shocking with chlorine after each use or on a weekly basis as you recommend with the continual ozonator my spa has? I look forward to your response. Thanks for your time regarding these concerns. Sincerely.

Keith R., 8/25/2008

Good questions. If ozone is being produced continuously, the need for a backup sanitizer is diminished. It is probably not a clear cut case of not being needed. More likely it is a case of being safe or being even safer. Depending upon bather load and other factors, a backup sanitizer is still a good idea. These same factors can determine whether, or not, periodic shocking is required. The purpose of the periodic treatment is to prevent the development of resistant microorganisms and not just to deal with bather wastes. You could probably do without the shock treatment, but it would be safer to do it once a month or a first signs of a loss of water quality. I hope that I have been helpful.

Sincerely. Alan Schuster, 8/25/2008


► Backup Spa Sanitizer Choice?

I just received a 200 gallon spa from our relatives about 5 years old. I plan on using bromine along with an ozonator. The question I have is the manufacturer recommend the use of lithium hypochlorite with the ozonator. They say a part cupful can be added by hand as needed. I am not sure of this, as bromine and lithium hypo are two different chemicals. I think they mean to use Lithium Hypo solely along with the ozonator. Could you please clarify this for me?

Bob, 8/11/2005

For proper sanitation, an ozonator should be used with a persistent sanitizer, such as bromine or chlorine. Bromine is very popular in this application. It can be added in a variety of ways and is essentially odorless. Lithium hypochlorite is less popular, even amongst chlorine types, and can produce some chlorine-related odors. I would use bromine on a regular basis, along with the ozonator. You could use the lithium hypochlorite, as a shock treatment to quickly boost the bromine level, as it will convert to bromine in a bromine-maintained spa. The choice is yours. I think the manufacturer was merely trying to make sure that you used a backup sanitizer with the ozonator. I hope that I have been helpful.

Sincerely. Alan Schuster, 8/11/2005

 
► Ozone And The Environment?

Will my spa's ozonator add to the problem with the Earth's ozone layer?

John H., 1/5/2006

No! The small amount of ozone produced will quickly decompose, back into oxygen, after leaving the spa. I hope this puts your mind, at ease.

Sincerely. Alan Schuster, 1/5/2006


► Pool And Spa Sanitizer Compatibility?

My wife and I recently purchased a hot tub. Expecting delivery shortly. The salesman is pushing biguanide like he owns stock in the company. Although he talked us into the ozone generator, he suggested we “unplug” it and use biguanide, as a sanitation regime. I am currently leaning towards the ozonator coupled with a mineral purifier and occasional shock as needed. Dichlor? Let me know! My concern is, we currently have a pool treated with biguanide. Our teenage kids will likely going between the hot tub and pool. Should we be concerned with any chemical incompatibility problems considering the two different sanitation regimes with the pool & spa? Your expert advise is welcome, as we are novices.  Great web site!  I also recently ordered your spa/hot tub book and look forward to reviewing its contents, so you are not bothered with more annoying questions from us! Many thanks.

Edward S., San Clemente, CA, 3/31/2004

Use the ozone generator and forget about the biguanide! You'll be happier in the long run, using the combination of ozone and a mineral sanitizer. With biguanide, you'll have foaming problems and a greater potential of resistant microorganism problems. The issue of compatibility is a really good question. Biguanide and any mineral sanitizer are incompatible. And yes, there will probably be cross contamination between the pool and the spa. Want to know what I would do under these circumstances? I would stop the biguanide in the pool and add an ozone generator and a mineral sanitizer. This eliminates any incompatibility and you should have quality water in both places. It is almost inevitable that sooner or later you will have to give up the biguanide. Pools that are maintained on biguanide seem to have a high probability, of the formation of a sanitizer-resistant microorganism, after a few years of use. Check the archives for biguanide in pools and spa to see some examples. Dichlor is appropriate and the questions are never annoying! I hope that you'll find this information helpful.

Sincerely. Alan Schuster, 3/31/2004


► Ozone And Monopersulfate?

After looking through your list of Q&A, I did not see anything about monopersulfate. I have a 500 gallons spa and I use an ozonator and spa shock. Also, because it is used frequently by many people, we were told to use a sanitizer. My question is, when I use the strip test it shows that the pH balance and alkalinity are good but the mps (monopersulfate) is at the very low end. The test strip shows a normal level would be purple in color and mine show white. What should I do to remedy this problem, and what happens if nothing is done to correct this. Thank you.
 
Nicole, 7/10/2004

You should use a backup sanitizer, with an ozone generator. However, monopersulfate is not a sanitizer. It is an oxidizing agent. I suggest that you use bromine, as the backup. You can either use bromine tablets in a floater or add a dose of sodium bromide monthly and continue with the periodic additions of the monopersulfate. The sodium bromide will be oxidized to bromine by the monopersulfate. With the ozonator, you should be able to have excellent quality water, by maintaining a bromine level of 1-2 PPM. Bromine can be measured on most spa test strips. During peak bather loads or whenever the bromine level is too low, just add some more monopersulfate to boost the level. I hope that the information proves helpful.

Sincerely. Alan Schuster, 7/10/2004

 
► pH And An Ozonator?

My spa is equipped with an ozonator and a Spa Frog Mineral Sanitizer. Does the ozonator affect the pH?

Greg M., Fresno, CA, 12/12/2006

The ozonator produces ozone by combining 3 molecules of Oxygen (O2) and forming two molecules of Ozone (O3). There is no affect on the pH. During the reaction of ozone with the organics wastes, by-products could be formed, that affect pH. The effect, in a properly balanced spa, should be minimal. The Spa Frog Mineral Sanitizer will help add stability to the pH, as it provides sanitizing action. I hope that this information is helpful.

Sincerely. Alan Schuster, 12/12/2007


► Why Do I Need To Add Bromine?

My spa came equipped with an Ozonator. I was told that ozone is a sanitizer. But, I was also told that I should maintain a low level of bromine. Why? Thank you.

Bill F., Kalamazoo, MI, 4/15/2006

Ozonators are, indeed, very popular in spas. The limitation of ozone is that once production has ceased, the ozone does not remain in the water for any length of time. There is no residual. Fortunately, in a spa, you can set the timer and pump to operate for periods throughout the day. This helps keep the periods, without ozone, shorter and that helps in the control of microorganisms. In order to assure that there is always some sanitizer present in the spa water, it is typically recommended that a backup sanitizer be used. In your case, the dealer suggested that bromine be used: a very popular choice as a backup. You will have to add much less bromine because you have an Ozonator and you should be able to keep it at a lower level(1-3 PPM, instead of 3-5 PPM). Ozone and bromine are a really good combination and the dealer made a good recommendation. Adding a SPA FROG mineral sanitizer will allow you to use less bromine to maintain this low level and will provide persistent backup sanitation. This product is a recognized spa water, that can be used with bromine or chlorine. I hope that I have been of assistance.

Sincerely. Alan Schuster, 4/15/2006


► Is The Ozonator Working?

Hi Alan. How can you tell that the ozone is working, I have a U.V. ozone generator approx. 2 years old. I am planning to use a mineral purifier and ozone, because chlorine gives me a rash and biguanide keeps clouding up within one week after filling. Should I buy a new ozone generator to be safe? Thank you.

Tom, 1/29/2010

I can't tell whether or not you need an ozonator, but you should check it out. Most ozone generators need a replacement bulb or part, after 2-3 years, more or less depending upon usage and conditions. Some ozonators have indicators that can determine, if they are producing ozone. You might be able to smell ozone, after lifting the cover. There are test methods that can be used to test for ozone. If you are not producing enough ozone, the mineral sanitizer alone will not be able to keep the water clear because it cannot destroy organic contamination and buildup: there would be a noticeable loss of water quality! The combination of ozone and a mineral sanitizer should work out very well for you. Just make sure that you maintain the other spa water parameters: pH, TA and calcium hardness. I hope that I have been helpful.

Sincerely. Alan Schuster, 1/30/2010


► Needing A New Ozonator Chip?

I have an ozonator and want to know how to check if it is operating. I was told as long as bubbles are coming out it is working. Have to add a lot chemicals to keep it in balance. Is it worth upgrading the system?

Larry C., 2/12/2005

Close, but no prize. Bubbling only indicates that the venturi, by which ozone is introduced into the return flow is functioning. This is not confirmation that ozone is being produced. Corona-discharge ozonators, such as yours, are capable of producing more than enough ozone and you should not have to add "a lot of chemicals." If you can't smell it, after removal of the cover, it is possible that no ozone is being produced. It could simply be that a new Corona Discharge Replacement Chip needs to be installed or it could be some other malfunction. The replacement chip costs a lot less than a new ozonator and is the most likely cause of the problem. You should refer to a product trouble-shooting guide for more insight. By all means you should restore proper ozonation, as it makes a big difference in spa water quality. I hope that I have been helpful.

Sincerely. Alan Schuster, 2/12/2005


► Ozone, Mineral Sanitizer And More?

I emailed you a month or so ago about mineral purifiers and ozonators. Since then I have tried using dichlor for shock only to find out that it gives me a rash for about 3 or 4 days. My pH and alkaline are in good shape and I run my ozone for 12 hours a day, 6 on 6 off. I'm going to go back to a non-chlorine shock. Do I still need to use a sanitizer like bromine or can I get by with just the shock, purifier, and ozone? Thanks Again.

Curt M., Hays, Kansas, 5/13/2009

You might just be sensitive to chlorinated cyanuric acid (dichlor and trichlor) and not necessarily to other forms of chlorine. It is hard to tell, from this limited information. But, you do know how to avoid the problem! Your ozonator should be able to meet most of the sanitizing requirements. Because ozone does not remain in the water for long periods of time, I suggest that you continue to space out the ozonation periods, throughout the day. The lack of permanence is the reason for the need for backup sanitizing. In this role, the mineral sanitizer works well. You should only need to add the non-chlorine shock after periods of heavy bather usage or upon signs of a loss of water quality. Good luck and enjoy the spa.

Sincerely. Alan Schuster, 4/13/2009


► Ozone and Ionization In A Spa?

An Ozonator was installed, in my spa, as part of the original equipment. I have been using chlorine as a backup. Would it make sense to add an Ionizer as a backup? Will it eliminate chemicals? Thanks.

Phil, Sausalito, CA, 4/4/2010

Makes sense to me. Adding an Ionizer, as a backup sanitizer will reduce the need for the chlorine. Inasmuch, as the Ozonator eliminates most of the need for shock treatment or other oxidizers, you should only have to control the pH and total alkalinity. However, for best results, maintain a free chlorine level of about 1 PPM, to act as a sanitizer backup. If you're looking for convenience, this should fill the bill. I hope that I have been helpful.

Sincerely. Alan Schuster, 4/4/2010


► Effects of Ozone?

Alan, I have read about ozone in which it is damaging to our lungs above 1ppm. I have a spa that ozone is injected 24 hours a day and can be smelled when entered. Is this dangerous in any way at all.  If so what can I do?  If I sit in the spa for 15 minutes or more, I can notice my chest getting tight. Is that from the heat or the ozone. Thanks.

Scott H., 3/11/2004

Yes, it is true that ozone can be harmful, especially in high concentrations. However, Ozonators do not produce high levels of ozone and much of it reacts with the wastes in the spa water. Elements of your question are clearly medical in nature and I suggest that you seek appropriate medical advice, as to the possible causes of your symptoms. There is something that you can do to reduce the airborne concentration. Have an exhaust fan controlled by a humidistat: this will help reduce the concentration. It is possible to have ozone production suspended during actual use of the spa. My spa did not produce ozone, with the high speed pump turned on. It only produced ozone with the low speed setting, which was controlled by a timer. The timer was set to avoid the most likely periods of use. I hope that I have been of some assistance.

Sincerely. Alan Schuster, 3/12/2004


► Ozone And Chlorine In A Spa?

I have been using a granular dichlor in my spa. The results have been OK, but I would prefer less chemical odor. Would adding an Ozonator help?

Bob C., CA, 12/15/2006

Definitely! Ozone will act as a backup sanitizer and allow you to maintain a lower level of chlorine.  In theory, all you need is a trace amount of Free Chlorine. To play safe, I would suggest a level of 0.5-1.0 PPM, as opposed to 1-3 PPM without the ozonator. In addition, you should find much less of the odors associated with the reduced chlorine use. Bromine, mineral sanitizers or ionization units can, also, be used in the back-up sanitizer role with ozone. I hope that I have been helpful.

Sincerely. Alan Schuster, 12/16/2006


► Ozone And How Much Chlorine?

Thanks for your website. I have a question. I just learned that the spa that came with the house I bought has an Ozonator in it. I don't know how old it is. I read all the responses on Ozone and Chlorine and I do not understand how I can know how much Chlorine to put in my spa? "Keeping a level of 0.5-1.0 PPM" sounds like a question of faith that the Ozonator is working and it is clear that they become less effective with time. As they become less effective, I would expect to be adding more backup sanitizer. But how much? Thanks.

Greg, 4/2/2007

The addition of an ozonator is something that will make maintenance easier and produce higher quality water. It will reduce the chemical consumption. Using an ozone generator helps reduce chlorine additions. However, how much chlorine is required will depend on the ozone output, how it is produced over time and bather activity. There is no set amount that you can add. Test the water and make additions, as needed. You can test for ozone, to confirm the unit is working. Visit the website test equipment store, for more information. For testing purposes, I suggest the LaMotte ColorQ all-digital Water Analyzers, as they provide the right kind of information. Because ozone levels are fleeting, you might add a SPA FROG mineral sanitizer, as well. The combination of the two work well together. All you should need is a very low level of chlorine, one half the usual level.  Bromine would be a better choice, than chlorine, as there is less odor and it is less irritating. You would need 1-3 PPM, when used with the SPA FROG. I hope that this information proves helpful.

Sincerely. Alan Schuster, 4/2/2007


► Indoor Ozone?

Alan, we are creating a spa room.  It will have a ceiling fan-vent and windows that open, but we do live in Michigan and will not be leaving them open all year.  We are looking at a spa with a Corona discharge Ozonator to place in the room.  We were told by that this would be dangerous and could cause dangerous health risks by being indoors.  Is this true?

Cathy in MI, 3/21/2005

Corona discharge units are capable of producing higher ozone levels than UV units.  That means in the winter months, with the windows and the vents closed, it is possible that the ozone will rise to unhealthy levels.  Even with some ventilation, you could still produce too much ozone.  You don't want to use the spa while ozone is being produced.  You need some safeguards that this will not happen!  Make the choice based upon your installation setup.  Good luck and enjoy the spa.

Sincerely. Alan Schuster, 3/21/2005


► A CD Or UV Type Of Ozonator?

Which is the better for an outside hot tub? a CD ozonator or a uv ozonator? Thanks.

Tony H., 4/11/2007

A CD ozonator can produce higher ozone levels, but the UV Ozone Generators are very capable units. For best results use, with a Mineral Sanitizer and a low level of bromine. I hope that this information is useful.

Sincerely. Alan Schuster, 4/12/2007


► Adding A Floating Dispenser?

My spa (200 gallons with ozonator) is being sanitized with chlorine. The tub is unattended for sometimes as much as a week. Is there a Dispenser that can chlorinate when we are not there? Thank You.

Al H., 9/8/2004

There are floating dispensers that could be used with chlorine tablets, but it is not something that I would recommend. The tablets are acidic and will dissolve too rapidly at the temperature of a spa. You should be able to get by with just boosting the free chlorine level to 3 PPM before leaving. If the ozonator is on a timer and the water was in good condition before, upon departure, the spa should remain in good condition. If you want to leave a floating dispensing in the spa, you can do it with bromine. The bromine product is slow dissolving, even at spa temperatures. You should be able to get by with the dispenser set at the lowest level. I hope that this information will prove helpful.

Sincerely. Alan Schuster, 9/8/2004


► Best Use Of A Spa Ozonator?

My spa is equipped with an Ozonator and I operate the pump (and the Ozonator) for 8 hours a day. We have it set to switch on about 9 hours before we normally use the spa. That way the water is warm and the conditions should be ideal. Is it better to run the spa for 4- 2 hour periods or 1-8 hour period?

J. D., 12/2//2006

I would prefer to operate the ozone generator for 4-2 hour periods, instead of a single 8 hour period. Ozone sanitizes best while it is operating. Having four runs per day will sanitize the water four times daily and make microorganism growth less likely. One 8 hour run will leave 16 hours without effective ozonation. You should be using a sanitizer backup such as: chlorine, bromine, mineral sanitizer or ionization. This helps assure sanitizer presence, during the periods that ozone is not being produced. I hope that I have been helpful.

Sincerely. Alan Schuster, 12/2/2006

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