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O3- ozone Q's?


Active Member
Well I am back to find out the scoop on O3. I have been running an O3 generator that is made for a hot tub. It is a Delzone ZO-300. I have a venturi inline that is backed by a HQ aquarium air pump. At the moment I only run it for 2 hours twice a day. I have resisted running it any more than that as I am worried that it might damage the plants. I "assume" that I am running it at the full 300 mg.hr. I say this because although I run the pump on low, it pulls quite a bit of air. I have not found the smell to be offensive but after two hours it is definately noticable. I have searched all over the net and have yet to find out how to monitor the O3 levels? ... Or for that matter, what the safe or recomended levels should be for plant growth. The best I could find is "if it smells like bleach then it is too much".
If anyone has any real life experience with O3 I would like to know if I am just being paranoid? Can I run O3 continuously or not? Is it better at night than in the day? What is a good mg.hr ratio to shoot for? Is there a monitoring device that I can get?
BTW... I use it only for problem control not odor. I have a 800 cfm fan (set at 250 cfm) and a large carbon filter. Room size is 130 cubic feet. Air is exausted to the attic and fresh air is brought in through passive intakes in the house.
Although I will probably continue to run this O3 set-up on a timer, I just want to see if anyone here can recomend a way of monitoring and keeping it at safe yet effective levels.
Thanx in advance,



New Member
First off O3 is bad for human exposure/consumption, so please be careful with overexposure. It's best to vent the room into a space separate from the grow and do the O3 treatments in there. It will also take away the smell away from your plants. Not so good for "bag appeal" if that's important to you.


Well-Known Member
o3 is also corrosive to rubber parts. The correct way to use o3 is to vent all air to be treated into a separate chamber, Treat for 15 minutes then evacuate the treated air. The air needs to be treated for several minutes for the 03 to work at 100% efficiency or else your just blowing the dirty air right through the 03 as you exhaust it.


Active Member
Thanx for the replies guys. I guess I forgot to include some info..... I am introducing the O3 directly into the flower room. As I said, only for two hours twice a day. As you can see by my CFM/cubic foot ratio, I am exausting/purging all the air at least once a minute. The O3 suppy tube enters just behind my oscilating fan and gets circulated around the room and then out through the carbon filter and then out to the attic. The room itself is air tight except for the passive air intakes... the walls of the room suck inwards due to the negative pressure. I would not be exposed to O3 unless I was IN the flower room itself... I am more concerned about the plants.
Just a little more info for you.... It is a UV O3 generator not a carona discharge so it is far safer without the harmfull off-gasses.
Here is a great link that gives a ton of info on O3. This is just one of many good sources on O3 but alas it does not answer my questions.

Ozone Properties and Characteristics - Ozone Properties and Advantages

Since my questions are related to pot plants it is not easy to find reference or info to answer my questions so this is why I am hoping someone here has some real life info to help,

Thanx again guys,

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Well-Known Member
I myself would never use it in the room with my plants. I would build a seperate treatment chamber and use it but never would I allow the o3 to be in the same room with my plants. You want to keep the odors from reaching other noses, not keep the plants from developing ANY odors. O3 is known to remove smell from the buds themselves when used in the grow room.


Active Member
Thanx again for conversing Racefan. I have to agree with your point about it adversly affecting the overall arouma of the plants.... although IMO the finnished product would not be seriously affected...?..or would it...? I HAD originally thought that I would use O3 to the very end and as well as a very small amout in the drying chamber to help prevent mould? I might reconsider.... food for thought...
Annnyyyway... that is that.
Now... I see you also returning to the point about odor control.... I must reiterate that I have no odor control issues. I have filters, venting and no neighbours... no worries about odor. I am only wanting to utilize O3 for it's other benefits... it has many, many other benefits!
I have alot of knowledge of ozone, I did a search on many MJ boards and read EVERY post. I also read EVERY article on the link that I posted and many other "googled" sites on O3, I also work in the spa industry and see thier applications frequently. So "why" did I post a question here if I know everything (LOL)... because there is no real data on using it for MJ other that for odor control. Besides I don't get that many reasons to post so I have to come up with something interesting to discuss. :) I have answered some of my questions already like how to monitor and where to get monitoring devices, as well as saftey and health concerns. I am just seeing if anyone else has used O3 for it's other benefits in relation to MJ growing.
At this point, unless I here otherwise, I plan on using my best educated guess... I will run it for one hour twice a day on a timer. It disapates in aprox one hour so it will be getting a decent amount that will surely fall into safe levels. Did you know that O3 kills spidermites?...(so the info says)... prevents bacteria and mould?... keeps bugs away... cleans the pores of leaves to allow beter resperation? It's benefits are exiting but first I need to know if anyone else has any real world experience.
Thanx again for the responses...



New Member
Well I'd just say...this IS a informational and educational cannabis site, so anything you can glean from your project please share with us all.

Everything I've read about it is in regard to health hazards and odor control so I'd love to learn more about it...especially in regard to pest and disease control.

thanks Stilletto!


Well-Known Member
There are benefits and there are disadvantages to it. IMO it's not beneficial enough to warrant use in my room. Others may feel differently and more power to them. lol Yes I know about some of the benefits from ozone. I have a dual outlet model sitting here right now. I used it for about 3 years before giving up on it. I know about using it to kill predators. They say it requires aprox. 10000 ppms over a hour or so's time to do it which has also been reported as a harmful amount for your plants. Plus there is the fact that ozone is a more telling smell to the neighbors than the actual pot is. I can say it's a skunk near by for the pot. How does one explain high level of ozone odor? < that was my main prob with it.

Here's a unrelated but sort of related to my prob of the smell story.

I grew up with asthma. A bad case of it. I transferred this disease to my children I guess because my second oldest daughter had it so bad we had to buy a pulmo aid machine and ozone machine to clear the air for her to breath easier. The ozone machine was a huge box that made the whole damn house smell so bad that no one would come over. (One might guess that clean pure air would smell good but they would be wrong. It stinks really badly) I got hassled so much from the cops over that smell! I guess living in the emerald triangle didn't help it any, but they thought I was growing huge. No one would purposely make their house smell like this unless they are hiding something is what they said. Over and over. I had to get a note from our doctor and go see the police captain and explain my situation to get the bastards to stop hassleing me. Eventually the box stopped working and we discarded it and hoped our daughter would live which she did. She's 20 years old now.

Now I know my story really doesn't relate to your questions and statements. I'm not suggesting that ozone isn't good for some applications. Quite the opposite actually. If using ozone is what you feel you need to do then go for it. I'll enjoy reading your posts about your findings and experiences. Keep us updated please.


Active Member
I'm back again...
Racefan... funny story... except the part about the athsma. LOL
I also have to agree that it takes a large dose to kill pests... more than is safe but I beleive it is more like 30-50 ppm. It will cause plant damage at .2 - .5 ppm. I would like to hear more about the one you used and the way it was used?
Now... I have been noticing a lack of info on this so I have been doing my own math and tests. It has literally taken 4 days and two sleepless nights to put togeather the equation and then solve it.... my work covers many pages of paper and I think I wore out my calculator! LOL
Keep in mind that 15 years ago I failed algebre repeatedly but I have a need to know certain things and I can't seem to rest till I have an answer. :hmmmm: I will be adding more to this thread as I continue to work out the math. This is just the start I think... ... to be honest, this info might not help anyone else as I am just using the figures for the gear that I am using... but if anything it will help to explain some of the math. Also I have tried my best to make this easy to understand and it is rather difficult to show the math as you can't use algebra style symbols in regular typeface.

Durring these trials I will be aiming to maintain a o3 level between .05 - .125 ppm/m3/minute. I am using the following perameters for my calculations: As mentioned before I have complete air exchange every minute in my room, 800 cfm max set @ 200 cfm less filter restriction = 130 cfm. My ozonator produces 300mg O3/hour. My air pump has a maximum flow rate of 2500cc/minute, set @ 33% power. My room is 130cfm = 5.9 m3.
First I must work out the capacity of o3: 300mg o3 = .3g o3/hour divided by 60 minutes = .005g o3/m3/minute.
Next I will work out the flowrate: 2500cc= 1.3 m3/min x .005g/m3/minute = .00065g/m3/minute.
FACT: 1gram o3/m3 = 467 ppm.
So... 467ppm x .00065g/m3 = .23 ppm o3/m3/minute. divide that by my 5.9 m3 room = .04 ppm of o3 concentration.
But... normal air has only a 20% concentration of oxygen... so... .04 ppm x .20 = .008ppm o3/m3/minute... far below my target.
If I turn my pump to high it will multiply that figure by 3 equaling .024 ppm/m3/minute. Still low.

At this point I will stop as I still have many calculations to complete. This is just the preliminary work. There are quite a few other factors that I have yet to work out.

Once again if anyone wants to add anything it could really help me out... the reality is that all this math means nothing... I just get crazy with shit sometimes.. LOL

Stay tunned...



Hi stilleto,

This sounds like an interesting experiment your trying to run, and it seems like some errors in calculations could have some troublesome effects since your optimal range boarders on the harmfull range. I'm willing to help you with your calculations and I think i should be able to handle all the math involved in this problem.

I am confused about one thing off the bat, and thats the ppm you wish to maintain. You stated:
"Durring these trials I will be aiming to maintain a o3 level between .05 - .125 ppm/m3/minute."

Now what really confuses me is the ppm/m3/minute, first off by convention the meter cubed should be written as m^3, but i know what you mean by m3. The real confusing part is weather you mean ppm/(m^3 * minute) or if you mean (ppm*minute)/m^3. I notice this kind of unsimplified units in all your calculations and it is a little confusing, If you need help with the rules for simplifiying equations pm me and let me know. Sorry to nit pick.

A few questions:
How do you know the flow rate with the restricion of the filter?

What is the air pump doing?

Is air exchange running when you add O3? (no keyboard symble for subscripts that i know of)

Thats all for now, let me know and i'll do some calculations and we can compare answers and discuss. But i need to goto class now.


Active Member
Cookieman... thanx for responding!
I bet my math seems confusing... I have no formal training! As I said, I flunked math. But in my years since then I have had to develop my own ways of solving equations. I will try to answer your questions then I will post my personal conclutions. This kind of thinking made my head hurt and I have decided that it is more work than it is worth! LOL
First off.. I guessed the rate of restriction. I figured a good restriction of 35% would apply for what I was doing... seemed realistic? Secondly... the air pump is pumping. J/K.. I used an aquarium air pump and a venturi. Yes the air exchange would be on durring o3 injection, that is why I figured I would use the figures at a minute ratio.
As to your other points... I was aiming for levels just shy of the max levels. They are only slightly higher than OHS regulations. And it was supposed to be ppm per m3 per minute. I just used "/" as "per".
Like I said it would be confusing... I am not a scientist... just an average Joe who really loves his hobby and is always trying to find ways to improve my situation and learn more about the wonderful hobby of botany! :)

I will post my conclution in another reply... feel free to critique my findings as I always like to learn more. :)



Active Member
I have decided that I have come to the end of this inquisitive experiment. I have drawn some conclusions and have decided not to continue using my ozone generator as an air quality enhancer. Here are my thoughts...
First of all it is very complicated as to proper dosage. Even in manufactured residential units there are no real numbers, they all refer to "if it smells like ozone turn it down... if you can smell household odors turn it up." I could find no real guidelines that can maintain control of ppm . I did however find OHS guide lines for safe usage and they are detailed but not in a way that can be easily monitored in a realistic way. BUT... there are monitoring devices out there that can give you output readings and levels but they are generally very expensive.
Next... even if we could accurately and easily control and monitor levels of o3 it would then be a matter of if it would be worth it? I do not think so... the levels needed in order to not damage plant life are lower than the levels needed to kill a lot of bacteria and mold. The plants would suffer first and more. Some bacteria would be affected at low levels but the funguses seen in grow rooms are generally of the more resilient variety. Some of the beneficial micro-organisms that plants have in their soil ARE weak and could easily be affected.
Also, as o3 is released it is combining with the air and other particles including co2 and breaking them apart to create an even higher level of oxygen in the space. This is the opposite effect than what we are after, in contrast we ARE trying to increase co2 in the air for flower growth. This should also be considered when using o3 for odor control in rooms or houses.
Another point, although I do not grow organically, the use of o3 would be even worse. It would negatively affect the "living soil" that is the heart of organic plants.
On another note... I had thought of injecting o3 into my water jugs to sterilize the water prior to adding supplements.... I am still working on this... I will update later.

Now how about some realistic uses? Well, I have concluded that it would work great to sterilize an empty room in between crops. Heavy doses can be used for shock treatment to eradicate mold or disease, even to eradicate pests. If you inject heavy amounts for an hour(with nobody home) then allow one hour for it to dissipate it would be a great sterilizer. Further more as we all know if o3 is used properly it is a great odor remover.

To wrap it up I will say this... It is fun to learn things for yourself, in the last couple of weeks I have really found this subject to be interesting. It kinda reminded me of crammin' for finals in school so many years ago. LOL.

Any comments or suggestions?...



Well I was thinking about the calculations on the way to class and I agree they are confusing and complicated and as you stated in your previous post they made you want to give up. There might be an easier way.

Is this kind of like CO2 inhancement where you want a certain ppm at all times?
If so you could use an O3 ppm meter to calibrate your room. Do this by running all the air exchange stuff with the O3 meter on and the O3 generator on and move it around the grow room taking readings at various places to get an average for the room. Then you can adjust the setting on the O3 generator untill the readings in the room are what you want. Eleminates almost all the math involved. This would also be the most accurate way to determine the ppm of O3 in the air as your model makes assumptions that haven't been tested (the resistance of the filter which we could determine experimentally). Additionally as you stated the O3 reacts with the molecules in the air such as the odor causing molecules and this will mess with calculations and dosage determinations since when the O3 is doing its benifical thing it is lowering the ppm. So this is becoming a very complex experiment to do this way.

The best way, in my opinion, to determine if low doses of O3 are benificial would be to run two identical grows in isolated rooms, one with a low dose of O3 and one without. Then compare the two rooms to see if there was benefit. You would want to do this with various settings on the O3 levels to see what the benefits are at different levels and see when it starts to become harmfull. This is beyond most growers means as they are lucky to have one room to grow in, plus this can double, triple, quadrouple, etc depending on how quickly you want to accomplish this goal. It may be possible to conduct this experiment under one light by using clear plexiglass to seperate the atmosphere of the control and experimental groups.

Using the O3 enhancement might be more benifical to hydro grows since you don't need to worry about killing benefical micro-organisms.
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