How Accurate is the “Green Machine”?

by | Last updated: Aug 2, 2018 | 11 comments

Updated January, 2019

Updated and corrected August 7th, 2018

After publishing this article I have received an email from Dr. Rowen who informed me about how unhappy he was with it because he felt misrepresented by it.

We have since exchanged numerous emails where I asked him a total of I believe four times to issue a clarification which I would then reprint and to point out the exact passage or passages which he felt were wrong.

So far, I have not received such a clarification or answer from Dr. Rowen. I hope he will still do so. He provided a correction on the prices he charges for the courses ($2,200 and $4,400, instead of as I said $3,000 to $4,000); and he also said that he does not receive a commission from any sales of Zotzmann generators. I edited the article accordingly.

Dr. Rowen’s main point of contention seems to be that he thinks that I alluded to the fact that he intentionally  “doctored” with the analyzer.

To make it clear: I never at any point said that nor alluded to any such thing. Any such interpretation by the reader is his or her own projection. Same for any interpretation of the article as me wanting to “take Rowen on”. I am just as baffled by those. I did not and do not wish to take Dr. Rowen on for anything.

Instead I *explicitly* stated that, if any possible mishandling happened, it was purely accidental, see here:

“Is this what the two doctors accidentally did without realizing it?”, when describing how one can reset the analyzer. How can this be any clearer that I did not believe in any intentional mishandling of the machine?

I am convinced that Dr. Rowen is a doctor with only the best of intentions for his patients and that he is not motivated by money or is out to mislead people. Here I am clearly saying that I believe he is NOT out to mislead people. How people take this to understand the opposite, I don't know. But it's their problem, not mine. 

Further I used the word “misunderstanding” to describe the whole matter, making it clear that I again believe that there was no intentional ill-will from Dr. Rowen or anyone else.

“This may not be the primary motive for his opinions on the Herrmann, but it likely does not give him sufficient incentive to look into the issue deeper and admit a possible mishandling of the analyzers.”, again stressing that his motive is not greed but a possible, above mentioned accident or unintentional mishandling coupled with misunderstanding.

After having exchanged lengthy emails with Dr. Rowen, I am more convinced than ever that Dr. Rowen’s opinions are based on what he saw and experienced and not on any ulterior motives. Something which I had already expressed in the article.

Another important note: I have since seen some of the videos. I don't know how many more there are. But none of the ones I have seen showed a negative ozone concentration on the analyzer. (What a negative reading would mean is explained further down.) But so far this means that the concentration being off because of an accidental mishandling of the analyzer is in my opinion very unlikely. 

I also realize that the problem has become extremely emotionally charged with both sides (Dr. Rowen and Herrmann) feeling wronged and attacked.

I continue to investigate the issue and will report on new developments.

Enjoy reading!

If you're an ozone doctor who's thinking about buying a 10-pass machine, or if you're a patient who underwent the 10-pass treatment, you may have come across criticism about the accuracy of one of the two available brands.

Doctors who own the Green Machine may be wondering, “Am I using the best equipment to get optimal results on my patients?”, and patients may be thinking, “Would I have reacted to the treatment better if my doctor used another generator?”.

If you belong to one of these groups, you'll want to read on.

I myself own a Zotzmann, the competitor's machine. And I think I may have been influenced by those rumors, too. Along with many others, I may have been misled into thinking that the Zotzmann is the only accurate 10-pass apparatus.

I have since changed my mind, because, as Dave Chappelle put it:

The Dr. Lahodny seminar

Around a month ago I was participating in an ozone seminar on the 10-pass ozone treatment with Dr. Johann Lahody, inventor of the 10-pass protocol. The seminar took place at the headquarters of Herrmann Apparatebau, the company which builds the infamous Green Machine. I'd been there before, but this time I was planning to get to the bottom of all the bad press. Translation: I was going to snoop around.

At the day of the seminar I arrived a little early — which was perfect for my snooping plans. I didn’t lose any time. I approached the first person who crossed my path and asked straight out, “Could I take a look at your assembly shop?”, since I had caught a glimpse of it on my way to the bathroom. 

The man was Marius Herzog, head of international sales, as I learned later.

“Yes, of course. Come with me,” he responded immediately.

His answer took me aback. In a good way. There was no hesitation, no “Let me check with the boss first,” no “Maybe some other time when we're better prepared.”, no “What?! The assembly shop? The most sacred place? Are you out of your mind?!”.

Marius simply turned and led the way to what I assumed was the Holy of Holies in the company's inner sanctum.

Dr. Johann Lahodny prepares to inject my arm during a workshop in order to perform the 10 pass treatment on me. 

Inside the Assembly Shop

The next thing I knew, we were surrounded by open 10-pass machines. There were maybe 10 or 15 of them. I was allowed to look inside them, and even hold an ozone cell, the heart of every ozone generator (it’s heavy!). In fact, I was granted absolute transparency, total access. There were no secrets here, it seemed.

It turned out that the Herrmann representatives weren't in the dark about me, either. Marius knew exactly who I was. He was aware that I had mentioned the rumor about the generator's alleged low quality in one of my previous articles. And for all he knew, I could have helped spread it. Still, he was more than happy to show me any area in the building.

But now I wanted to go one step further. 

“Could we test one of the machines during the break?”

“Yes, of course,” he said. 

“And could I film it?” 

“Yes. Absolutely.” 

Again, no hesitation, no deflection, no obfuscation. He was happy to oblige. Simply giving a woman what she was asking for. Marius, I thought, I like you. 

This was getting really interesting and really not the way that I had expected. 

Marius Herzog showing me around the assembly shop of the Herrmann Apparatebau headquarters. We were surrounded by open 10 pass machines.


In the end, things turned out a little differently than planned that day. The somewhat chaotic seminar didn't really have a break. And by the time I was done squeezing every bit of information out of Dr. Lahodny the employees had already started packing stuff and putting equipment away.

Insisting on performing the test right then and there would have been terribly insensitive. After all, it was a Sunday, Germany's official day of rest by law. Keeping people at their workplace on a Sunday would have been the height of callousness. So we rescheduled for the upcoming Wednesday.

The Questioning

Three days later, I was back with my iPhone and my creaky tripod. Marius had with him Johann, who serves as both the head engineer and the head quality manager. They had already prepared an ozone generator and an analyzer. But before we started shooting, the guys set me down at a table to have a little talk.

The situation reminded me of a scene where two FBI agents interrogate a suspect. It made me slightly nervous. What was this about?

It turns out that's exactly what they wanted to know from me.

“So, why are you doing this? What is the purpose of the recording?”, they asked.

“I want to know the truth. I need to see for myself how accurate the Green Machine is.”, I said.

The moment I uttered those words, the pair visibly relaxed.

It was clear that when it came to questioning the quality of their product, emotions were raw, and the company's representatives felt attacked. But the moment they were given the opportunity to have the machine speak for itself, they relaxed. They knew it wouldn’t disappoint.

An unexpected move

Before we started shooting I had one more request, though. I said, “I see you've prepared and selected an ozone generator and an analyzer. I'd like to suggest picking different machines, just to avoid the impression that we conducted the tests with staged equipment.”

Johann was a little hesitant at first.

Getting another generator meant pulling one out of production, one which had to be shipped the same day or within the next 24 hours. Using it for the video would mean holding up the fulfillment of the order. Still, he did as I requested, bringing along a different ozone analyzer as well. So we ended up testing two different 10-pass ozone machines with two different ozone analyzers.

This was a move nobody had anticipated that day.


You can see the results in the videos below.

The following testing was performed with the generator which has been pulled out of production with the 2 different ozone analyzers.

Analyzer 1:

Set concentration in mcg/ml  Measured concentration in mcg/ml, Analyzer 1
30 29.2 to 29.6
50 48.9 to 49.2
70 67.8 to 68.5

Analyzer 2:

Set concentration in mcg/ml  Measured concentration in mcg/ml, Analyzer 2
20 18.2 to 19.4
40 38.8 to 39.4
80 81.0 to 81.4


The ranges are due to the fact that ozone production is a highly unstable process. The built-in analyzer continuously measures it and the generator continuously adjusts so that the output stays in within the given tolerance range.

When I started shooting I had no clue what the analyzer would show. The recording was completely unrehearsed.

The video shows the testing of the Green Machine. Everything was unrehearsed. The machine produces ozone concentration within 1 to 2 mcg/ml of the chosen setting.

We chose a concentration of 55 mcg/ml on the ozone generator. The analyzer showed 55.5 mcg/ml. The generator is the “prepared” generator. 

Bottom line

In my opinion, the Herrmann Green Machine is The Shit, meaning an outstanding piece of equipment. I've seen its output tested in an unrehearsed, unstaged session. Not only is it a very accurate, but it's designed by top German engineers and manufactured by individuals who carry out their jobs with passion and conviction. I believe that the Green Machine is even surpassing the Zotzmann. More on that in an upcoming article.

In conclusion, the whole company — from the brand-new, spotless, state-of-the-art building to the ultra-friendly and professional staff — made a remarkable impression. Herrmann employees take pride in their high-quality equipment. And the company's R&D team is constantly working on how to build a better ozone generator for their customers. 

And the best part: you can get it in pink. Which basically settles the whole affair. I should have probably mentioned it first, then we could have saved ourselves this whole discussion. I mean pink, PINK!!! Do I need to say more?

Addendum: the Rowen Controversy 

How did this whole misunderstanding start to begin with?

A quick recap for those who didn’t read the notorious memo: Dr. Rowen and Dr. Robins, two generally highly-respected ozone pioneers, obtained a Herrmann generator and set up testing with their own Teledyne ozone analyzer. Results showed the machine to be off by around 20 mcg/ml. 

After that, Dr. Rowen described the results of the testing in a type of internal report. There, he referred to the Herrmann generator as the ‘Green Machine' for the first time, and claimed his testing results revealed the device gave inaccurate readings. The email subsequently circulated throughout the internet, the nick-name caught on, and the reputation of the company's generator became tarnished.

Possible Explanations

So how and why did Dr. Rowen find such inaccuracies in the ozone levels when he and Dr. Robins tested the Hermann generator? I came up with three possible scenarios:

1. Mishandling of equipment

Mishandling of the machine. As you can see in the below video, an ozone analyzer can be easily tricked to show a wrong and much lower reading by pressing the reset button. Is this what the two doctors accidentally did without realizing it? People who have watched videos of the Rowen testing say that they saw a negative reading on the display of the analyzers. If this is true, it proves beyond any doubt that the analyzer had to be reset at some point, since an ozone generator cannot produce a negative ozone concentration. The only way how such a negative reading would come about is if the machine had been zeroed out when the reading was showing a positive ozone concentration.

Disclaimer: I haven’t seen those videos. I have been told that they have been blocked since.

Update, August 7th, 2018: I have since seen some of the videos. So far none of them showed a negative reading of the ozone concentration. 

The video shows how pressing on the “reset” button on an ozone analyzer can render a falsely low reading. 

2. Different analyzers, different results

Depending upon the brand you use, you can get a reading from one analyzer which may differ from a reading taken from another. For instance, Dr. Rowen used US analyzers from the Teledyne company. According to Teledyne, their devices can produce a reading that's up to 10% off in comparison to the equipment made by their European competitors.

How can this happen? First, analyzers may use different technologies for measuring ozone. Second, there's no universal standard which defines an ozone molecule. When it comes to the meter for example (meaning the measure of length in countries which use the metrical system, just like foot is used in the Empirical system), the original model for the meter was established in the 1790s, based on what was thought to be one 10 millionth of the distance from the North Pole to the equator. And in 1799, a bar was actually made to serve as the prototype.

No such prototype exists for ozone. So there is no way to check if an analyzer truly renders a reading which would be universally accepted as correct. Hence Teledyne’s disclaimer.

3. Competition

I am convinced that Dr. Rowen is a doctor with only the best of intentions for his patients and that he is not motivated by money or is out to mislead people. I think that the above explanations are the most likely reasons for the readings having been off when he performed the tests.

But fact remains that he is the reseller of promotes Zotzmann machines in the US, for which he receives some accessories for free. He also sells trainings on how to use the generator. The workshops run between $3000 and $4000 $2,200 and $4,400 for a 1-day or a 2-day course, respectively. With the popularity of the 10 pass soaring, business must be booming.

This may not be the primary motive for his opinions on the Herrmann, but it likely does not give him sufficient incentive to look into the issue deeper and admit a possible mishandling of the analyzers.

By the way: the Herrmann generator requires no such additional expense. Instructions are conducted via a Skype call with Marius. Free of charge.

Also the training Dr. Rowen offers seems to be unique for the US market. When I bought my (refurbished) Zotzmann, the coaching was already included in the price. I didn’t pay anything extra. Same thing applies when buying a new machine.


I'm not an affiliate of Herrmann, and this message is unsolicited. I don't benefit financially or otherwise from the sales of any Herrmann equipment. No deals or compensation of any type have ever been discussed between me and Herrmann.  

My opinion expressed in this article is based on the demonstrations I've been shown. I've never owned or operated a Herrmann.  

The two ozone analyzers used in the testing described above are both property of the Herrmann company. Keep in mind that ozone analyzers in Germany need to be regularly calibrated. Once they are, they receive a sticker with a due date for the next calibration. The company said I am welcome back anytime to bring my own analyzer and repeat the testing.

Do you have questions or suggestions? Let me know in the comments below! Thank you.

About the author:

PaolaI’m Paola the Crazy Old Ozone Lady behind The Power of Ozone. I’m a licensed naturopathic practitioner, natural health consultant, ozone therapy enthusiast, researcher, and ozone therapy analyst. I hold certificates in ozone therapy, hyperbaric ozone applications, Oxyvenierung, and the Andrew Cutler chelation. I own several ozone generators including a German hyperbaric 10 Pass machine. I have been using ozone for over 13 years, I’ve chelated with the ACC program for close to 5 years and I’ve been carnivore for nearly 1.5 years. This website serves as a resource for those who are interested in ozone therapy and other approaches to successfully manage chronic conditions. 

Legal Disclaimer

Information provided is for informational purposes only and is not a substitute for professional medical advice. No health claims for these products or treatments have been evaluated by the United States Food and Drug Administration (FDA), nor has the FDA nor any other medical authority approved these treatments or products to diagnose, cure, or prevent disease. Neither The Power of Ozone nor the manufacturers of these items are responsible for the misuse of this equipment or the information on this page. It is highly advised to receive professional council from a licensed doctor before using ozone therapy or any of the mentioned products or tests on yourself.

Affiliate Disclosure

This website contains links to vendors of products I endorse, including If you decide to make a purchase through one of my links, they will pay me a commission. This does not influence my opinion about the products, as you can see from my reviews.


  1. Fred

    We bought our ‘Herrmann' just 6 weeks ago.
    Because I asked about it, Marius showed us the precursor of the current 10 pass machine. That precursor is currently being sold under the name ‘Zotzmann', so we were a little surprised 😉
    I cannot upload a photo, but I gladly send it to Paola. Thank you for your good site and your honest information, otherwise we would always be pressing a foot pedal …

  2. Pavol

    Sooo wonderfull seeing Dr. Lahodny still going strong!

    He is one of the few great men of current medicine.

    Great thanks for this blog and wish you all well, Paola!

  3. Hamid

    Dear Sir or Madam

    Hi ,

    I am Manager Samrra AL Sahel Company from UAE , we have two company in Dubai and oman , Now we're cooperating with companies in Germany , Japan , America Ultra solutions , KPI , Providian Medical , soma technology, UMI , we would like to cooperating with your company.

    Please give us good price for the following item :

    1- Ozone Therapy Haymmer New or Refurbished

    Hope to cooperate with your esteemed company.

    Best Regards

    Eng : Hamid


    U.A.E , Dubai , International City , Spain Cluster , Building No, S 16 , Unit No : 103
    P.O.BOX : 116735 , DUBAI . UAE
    TEL : 009714 4315872 FAX : 009714 4580558

    • paola d

      Hi Hamid,

      I don't sell any ozone machines, so I can't make you any price offer.
      I suggest you contact Herrmann directly:


  4. Graham Jessop

    Is there any chance you could test the Promolife, Status and Synergy models as most of the people on your ozone facebook group will probably use one of these 3 machines.

    • paola d

      Hi Graham,

      yes, I will do that.
      I would need to rent an analyzer for that.


  5. Dasha

    very interesting–love to hear comparative reports and of course, a good sense of humor is appreciated; I have had one pass o3 iv but only a few.

    I have couple questions:
    Can I find out if I am facing trouble during or post o3 tx (adverse reaction) without any genetic testing?
    I am probably dealing with: Borrelia, Chlamydia p. or Babesia or both, Bartonella, viruses, candida, parasites—is O3 strong enough to kill parasites?
    Who does the 10pass in the US, Mexico and would you recommend Dr Lahodny in Austria (does he practice)–I go visit my Czech family and maybe able to swing over to Austria (next door).

    • paola d

      Hi Dasha,
      thank you for stopping by and reading my article.
      I don't know of any testing, genetic or otherwise, which would be able to predict your reaction to O3.
      And yes, ozone could kill all those parasites. But it often depends on how much ozone you do, how often, which type, and for how long. And if you can get past the Herxheimer reaction.
      I suggest you join the Facebook group “The Ozone Group”, there you can find a list with doctors who do the 10 pass.
      Yes, I recommend Dr. Lahodny, also because he is very affordable. Yes, he does practice!

  6. Blanka

    This shows how careful we have to be before any conclusions are shared. Great work Paola! Thank you for clarifying the issue!!

  7. Dr. Isadora Guggenheim

    Finally vindication for Herrmann who was viciously attacked with false accusations. It is marvlous accurate equipment.

    • Kim Larson

      I am a naturopathic Doctor trained in US and currently have a clinic in Panama.I attended the Ozone without Borders conference in Aruba in April.I also paid for training by Dr.Rowen on the ten pass (Zotzman machine).I was delayed leaving Panama because I didn't have a “yellow card”.So I recieved the yellow fever vaccine and was a day late for the conference.The organizer told me no problem I would get a full copy of the videos no charge.
      The Training on the ten pass was a sales pitch for the 5000.00 two day training in the US.They could only perform 4 passes because they said they didn't have the
      supplies they needed.
      They made the Zotzman look very complicated with a foot pedal that needs constant attention.Also was saddened by the profanity used throughout the training (wanted to install vid angel on my ears)
      I went to the Zotzman table another Dr.was there with Mr.Zotzman selling his 5000.00 training in NJ.I was told by Dr.Zotzman himself that they supplied no training and I would need to get additional training in US and all support would come from them.Also three month wait on machines..they build them by hand.However throughout conference they would talk about “the other machine”.
      I returned to Panama researched the other machine and have not looked back.The Hermann is amazing and the customer service outstanding.It is so simple and the trainer is always there to provide answers.
      The Ozone without Borders group never provided the videos they promised..told me he never remembered the conversation.I was never put on their forum (I am assuming because I didn't sign up for US training and buy a Zotzman).Made some great connections there.Mr.Zotzman did call me 4 months later and said my machine was ready.I was already up and running with the Hermann.
      Just so you know in the 2 day Rowen training the Drs.just watch and never work on a patient.The real challenges are finding good veins for such a long procedure and keeping the treatment to one ISet…There is a learning curve.We are getting there.


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