# What happened to all the dissolved oxygen in the DWC cannabis grow?



## B3henry (Dec 10, 2017)

Internet DO Charts dont lie and real DO Test dont lie, but the charts and test are seriously conflicting.
The internet DO charts do not jive with the actual DO test results which I found was nothing like the DO chart predicts and absolutely shocking, but true and correct after 10 different DO test. The DO chart prediction and the actual DO test were all very different 100% of the time. If you believe the DO chart prediction is whats happening in your DWC cannabis grow, well, you are in for a major disappointment and real enlightenment.
I doubt that anyone of a cannabis forum ever tested DO in a DWC grow. And who would ever question the actual DO hydroponic DWC grow vs. the internet DO chart prediction and forecast.
Clearly, the only way to discover the real deal is to test the DO so I bit the bullet and actually tested the DO. Of course I did not buy a $100 DO meter, but I did buy a Salifert Dissolved Oxygen Test Kit which was in line with my test equipment budget. This DO test kit contains 50 test strips, cost *$22.31 and shipping was free.  Each test cost $0.50 which is reasonable in my opinion.  * https://www.amazon.com/Salifert-Dissolved-Oxygen-Test-Kit/dp/B001EJ3DQ4 My pH meter cost $150, but it is a good one and worth the money.
The DWC forum gurus claim you got to have 100% DO Saturation in reservoir to prevent the low oxygen problems like preventing roots from suffocation and Pythium outbreaks which all sounds logical to me. They also say you must have a water chiller to insure plenty dissolved oxygen, nothing else does the job. They say fungi thrive in low oxygen environments and oxygen rich environments (DWC reservoir water) promotes excellent root and aerobic microbial health. DWC gurus claim that oxygen rich reservoir environments play a major roll preventing fungal outbreaks and disease infestations.
Heres what I discovered this discovery was totally unexpected, shocking! 
DO chart prediction at sea level, fresh water, *NO aerobic plants/microbes in the water consuming Dissolved oxygen  no aerobic metabolic processes going on in water*
*DO Chart Prediction: 80 F water temp  DO concentration 8.0 PPM DO  DO Saturation 100%*
Real time DO Test in reservoir water containing mature cannabis roots and Great White beneficial microbes (1/2/ gallon or 4 lbs.)
*DO Tested: 80 F water temp = DO 4.1 PPM  DO Saturation 51%*
*_______________________________________________________________________________ *
DO chart prediction at sea level, fresh water, *aerobic plants/microbes living in the water consuming dissolved oxygen necessary for aerobic metabolism*
*DO Chart Prediction: 70 F water temp  DO concentration 9.0 PPM DO  DO Saturation 100%*
Real time DO Test in reservoir water containing mature cannabis roots and Great White beneficial microbes (1/2/ gallon or 4 lbs.)
*DO Tested: 70 F water temp = DO 4.8 PPM  DO Saturation 53%*


The DO chart predictions and the DO Test do not jive Why? So where did all the dissolved oxygen go?
Keep this in mind the next time a water chiller sales shows you a DO Chart justifying the necessity of buying a $400 water chiller.
Test the DO and see the difference. I can see now why there are many growers that look at their DO chart and cannot understand why they have caught the Pythium fungal disease.
The Question I have for you DWC cannabis growers is: *Do you have any idea what happened to all the dissolved oxygen in the DWC cannabis grow?*
The dissolved oxygen certainly did not off-gas nor evaporate into the air.


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## Growdude (Dec 10, 2017)

give it a rest


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## B3henry (Dec 11, 2017)

Growdude said:


> give it a rest


 
This is really cryptic stuff, confusing, disturbing, too complicated to imagine or even think about for some hydroponic growers, but the facts are real. Nearly ½ of the DO predicted by the internet DO chart is gone, vanished without a trace. The proof is the actual DO test of the reservoir water compared to the DO chart prediction.
Clearly you have no interest where or even why all that DO simply vanished. 
Appreciate your time and opinion.


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## RubyRed (Dec 11, 2017)

Heavy


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## pcduck (Dec 12, 2017)

> The Question I have for you DWC cannabis growers is: Do you have any idea what happened to all the dissolved oxygen in the DWC cannabis grow?



B3Henry why don't you enlighten us with a response to your own question? Maybe that way we could help you. So that this ( 





> This is really cryptic stuff, confusing, disturbing, too complicated to imagine or even think about for some hydroponic growers


 ) doesn't have to keep you awake at night, thinking about it. As it is really quite simple.:aok:


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## B3henry (Dec 12, 2017)

"As it is really quite simple. Feed the soil"  Really?

duck, thanks for tuning in and responding, but this question is actually directed toward  DWC growing and has absolutely nothing to do with dirt farming. I don't think this is something that would be of the any interest to dirt farmers that &#8220;feed the soil.&#8221; You know what I mean?

On the other hand, Low oxygen problems in reservoir may be of interest to some DWC growers that are concerned with root rot and fungal outbreaks. Again, I can see where this thread would be of interest to dirt farmers that "feed the soil."

Where do you think nearly ½ of the DO disappeared to duck? If it&#8217;s so simple, please tell a simple person like myself just where the O2 went.

I would like to hear your opinion, if you have an opinion though, thanks.

And I do understand that the clever Chinaman always answers a question with anther question. That's cool.


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## pcduck (Dec 13, 2017)

B3Henry you obviously do not understand what the term "feed the soil" means in organic gardening. Just as you do not understand the purpose and use of DO in DWC gardening.

All of your posts here, on this forum, are extolling the merits of DO in DWC gardening, but never answers any questions that are asked of you. We cannot help you if we don't know what you don't understand. Just because you can copy and paste, someone else writings, doesn't mean you understand them, which is apparent.  

The only information that I have gathered from your posts are:
1) you don't like chillers
2) or their salesmen
3) you are able to change the "laws of physics" (which is quite remarkable)


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## The Hemp Goddess (Dec 13, 2017)

LOL, I don't know where the DO goes, but I know where the hot air is.


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## B3henry (Dec 13, 2017)

The Hemp Goddess said:


> LOL, I don't know where the DO goes,


Finally, a straight forward simple answer to my question. Bravo.


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## B3henry (Dec 14, 2017)

pcduck said:


> B3Henry you obviously do not understand what the term "feed the soil" means in organic gardening. Just as you do not understand the purpose and use of DO in DWC gardening.
> 
> All of your posts here, on this forum, are extolling the merits of DO in DWC gardening, but never answers any questions that are asked of you. We cannot help you if we don't know what you don't understand. Just because you can copy and paste, someone else writings, doesn't mean you understand them, which is apparent.
> 
> ...


duck,  dissolving gas (O2) in water in DWC horticulture applications and beer brewing are actually solidly based in  chemistry laws, not physics laws. The colas, Sprite, 7-UP, beer and Champaign drinks are all supersaturated with gas (thanks to manipulating chemistry laws aimed specifically at achieving gas supersaturation) and in a hermetically sealed container to prevent off-gassing to atmospheric tensions. Again this is not a matter of physics. 
The difference between basic elementary chemistry and physics is major, like comparing freight trains to pick up-trucks in my opinion. These 2 fields of science are often very confusing for many people.

Heres a piece published this year I find somewhat enlightening, but even this piece about understanding DO in cannabis cultivation fails to address my question, much less answer the single 1 question I ask in this thread which is:   *Do you have any idea what happened to all the dissolved oxygen in the DWC cannabis grow?*

Cannabis Industry Journal  -  March 29, 2017
https://www.cannabisindustryjournal.com/feature_article/understanding-dissolved-oxygen-in-cannabis-cultivation/


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## samarta (Jan 10, 2018)

As in my hydroponic post to you B3, I do nothing besides hitting my numbers and I think it works!!! 

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## zem (Jan 10, 2018)

ime here, that is many years back, pcduck has always been resourceful in knowledge regarding DWC.
about the DO I think it is not complicated. So if the level of DO is 53% at 70F vs 51% at 80F this 2% could be the difference between night and day. and then the accuracy of the 0.5$ test is at question.
And even if for example you reach a very high level of saturation at 50F, the plant will be cold, it is not living only on DO so growers manage environment to make it favourable for plants in all aspects. Maybe the plant just does not require a 100% saturation of DO. If this question is troubling you, you could find loads of info about it. You cannot blame DWC growers for being in your opinion, not anal enough about DO levels


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## samarta (Jan 13, 2018)

Enough is enough, let SEE yours!!


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## Hushpuppy (Jan 16, 2018)

to answer the DO question: the oxygen is either A. used up by the plants' roots. Or B. as the temperature rises, the oxygen gets enough heat energy to separate from the solution and leave in the exhausting air. Much the same way evaporation works. Or possibly C. to a smaller degree, some of the oxygen gets locked up in molecular structures with other elements within the solution. It may get taken in by the plant or the heavier molecular compounds may precipitate out of the solution and fall to the bottom of the reservoir. 

Like PC said, there are more factors at play here other than just DO. Its the balance that is struck with all of these factors that produces the best outcome. In nature there are even more factors that control the plants' growth, but in controlled indoor grows, WE cant imitate nature. So what we have to do is get all the major factors (light, temps, air, nutrients, etc) as close to what makes the plants happy as possible. When your plants are happy they produce lots of happy flowers for us.


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## Hushpuppy (Jan 16, 2018)

I CAN tell you this much, when I get done with a grow, I have to cut away the roots from around all my air stones as they literally grow around the air stones to get that oxygen. But they are always happy, right up to harvest


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## Hushpuppy (Feb 5, 2018)

Something just dawned on me while I was talking to SoPappy about plants in hydro. I think our scientifically engaged friend miss one critical thing. When I run my bubblers, my pumps are sitting where they are sucking in lots of oxygen rich air. So ALL them bubbles that continuously run through my tanks, they are continuously replenishing the free DO in my solution so that my roots that hang there are quite happy. I must be doing something right


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## sopappy (Feb 6, 2018)

zem said:


> ime here, that is many years back, pcduck has always been resourceful in knowledge regarding DWC.
> about the DO I think it is not complicated. So if the level of DO is 53% at 70F vs 51% at 80F this 2% could be the difference between night and day. and then the accuracy of the 0.5$ test is at question.
> And even if for example you reach a very high level of saturation at 50F, the plant will be cold, it is not living only on DO so growers manage environment to make it favourable for plants in all aspects. Maybe the plant just does not require a 100% saturation of DO. If this question is troubling you, you could find loads of info about it. You cannot blame DWC growers for being in your opinion, not anal enough about DO levels



dammit, this was the ONE place I thought could visit without ANAL
I wish I could put an ANAL filtre on my browser, we should have stopped them at the rainbow, I don't want this ANAL stuff in my face!

just playin'w with ya, Zem


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## sopappy (Aug 24, 2018)

Hushpuppy said:


> ........... my pumps are sitting where they are sucking in lots of oxygen rich air. ........



I ordered a couple of pumps to use for re-circulating and the pump had an air hose attached to it. I almost ignored it and then thought.... waaaaait a minute, and they work superbly, look at that bubbly fountain. At the other end, I cut the drain so the return water actually falls through the air, you can hear it splash.
I'm not adding any stones to this tank. or should I? Is it possible to have too much oxygen?


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