Rdwc – What Is Optimum Do Sat Necessary For Plants And Microorganisms The Entire Growing Season?

[J Henry]

They say having "plenty of oxygen" is vitally necessary for successful RDWC Hydroponics. Does "plenty of oxygen" mean "plenty air" or "plenty aeration?"

Need some of your expert opinions with this one. Having no luck finding anyone that has any idea what DO Saturation is really requires and necessary to sustain plants and microbes ( 2 symbiotic eco systems) throughout the total growing season… is "plenty of oxygen" 20% DO Sat, 50% DO Sat, 89% DO Sat, 100% DO Sat….. What about 110% - 130% DO Supersaturation to guarantee, insure no possibility for the plants and the microbe colony to never to suffer low oxygen levels, environmental hypoxia, death and disease for the total growing season.

When you yank the covers back on the plain truth, is low oxygenation ever really any problem for any grower? Or are your chances of having any low oxygen problem negatively affecting your crop remote like winning Powerball.

Hydroponic equipment and chemical/nutrient salesmen and even “farming pro’s” I’ve talked with in the last few months do not talk about the aerobic microbe's biological oxygen demand, the volume of oxygen required and consumed by microbial colonies in DWC, but all of these salesmen and farmers tell me it is vitally important that “I must have 'plenty of oxygen' for the plants”… microbes, the tiny aerobes you can’t see, consume their fair share of oxygen too, but the little fellows that are so important seldom enter the total DWC DO equation discussion for some reason. The little fellows are tiny, but many billions of them thrive and multiply hourly a healthy DWC's; out of site-is out of mind perhaps. They also need a considerable amount of oxygen too.

So, does anyone happen know or have any idea what the optimum/ideal DO saturation is? The ideal number on wished for on the DO Meter that guarantees/insures a safe oxygenated environment for all the plants plus all the microbe colonies in RDWC’s?

Question: If you test the DO Sat with a DO meter and discover you do have a serious low oxygen problem in your water, how do to fix this low oxygen problem in your water? Are do you do nothing and hope the problem simply fixes itself before everything wilts and dies or becomes diseased and dies….

Oh No Mr. Bill - Another Crop Failure!

If you don’t know the ideal DO Saturation for sure, do you know a plant physiologist that teaches DWC at any University or College that will know for sure? They say that it’s real important in hydroponics to have plenty of oxygen…. I want to know what “plenty of oxygen” really means. Oxygen analyzers and DO meters are always available for precise oxygen measurement that eliminates the hoping, guessing if there is really enough oxygen to sustain a healthy environment.

Thanks

J

 

[Junk]

When you yank the covers back on the plain truth, is low oxygenation ever really any problem for any grower?

"Problem" is not the word I would use. But I think a lot of hydro growers are not getting maximum results. I have yet to reach a point where the water is too oxygenated.

Here is a chart. But basically, at the temps we operate the water at, at sea level, 9.1mg/ml is saturation point.
http://www.hakkoairpumps.com/subcat15.html

I'll tack my aeration setup at the bottom if you care to see how far I have gone, & I think it would benefit from more.

But to get back to it....I have a lot of oxygen....a lot...& I think if I were to add more it would be even better. Perhaps soon I would reach saturation levels of possible O2 in the water, but the infusion method would need to be updated. Meaning, Aqua lungs, do a much better job of dissolving the water, but I can't afford to run those in every bucket. Aside from the fact that they are so large. So, I think you could reach "possible saturation" points....but it would be quite expensive to get all that air infused into the water. Standard air stones don't do a good job of it.

So, I guess what I'm saying (I'm sorry, I'm waking up slowly today) is you could have enough air pumps to achieve maximum O2, but you would need to get that infused/dissolved into the solution, which standard air stones do very poorly.

They say having "plenty of oxygen" is vitally necessary for successful RDWC Hydroponics.

They, are absolutely right. From what I've seen, you can't achieve too much DO. Though I've not measured mine, just going from observing the plants.

Does "plenty of oxygen" mean "plenty air" or "plenty aeration?"

Yes, they mean plenty of DO, lots of it.

Having no luck finding anyone that has any idea what DO Saturation is really requires and necessary to sustain plants and microbes ( 2 symbiotic eco systems) throughout the total growing season…

At the temps we operate the water at, seal level, optimal barometric pressure, no salt, 100% saturation = 9.1 mg/l

Here are two sites to give you an idea of what you are driving at. If you aren't going to read all of it, some basics are:
The atmosphere can hold different amounts of water vapor (humidity) depending on the temperature. That's why it's called relative humidity. The hotter the air, the more water it can hold. You probably know all that already.
Water is much the same, but reversed. Water can hold different amounts of O2 depending on the temp of the water. But the colder the water, the more DO it can hold. Salinity also has an effect, sea level, atmospheric pressure. You need to be above 5mg/l for average marine plants. Cannabis though, is not a natural marine plant. From what I've seen it will take all the DO you can throw at it.

http://water.usgs.gov/edu/dissolvedoxygen.html

20% DO Sat, 50% DO Sat, 89% DO Sat, 100% DO Sat….. What about 110% - 130% DO Supersaturation to guarantee, insure no possibility for the plants and the microbe colony to never to suffer low oxygen levels, environmental hypoxia, death and disease for the total growing season.

100% is ideal
http://fivecreeks.org/monitor/do.shtml

do not talk about the aerobic microbe's biological oxygen demand, the volume of oxygen required and consumed by microbial colonies in DWC,

That's because it's much lower than what the plant needs. So if the plant is doing ok, the microbes should be ok.

The little fellows are tiny, but many billions of them thrive and multiply hourly a healthy DWC's; out of site-is out of mind perhaps. They also need a considerable amount of oxygen too.

Considerable isn't the word I would use. Billions of them are invisible to the naked eye. But they are also creating oxygen as they do their thing. So, if you have any amount of quality aeration, they should be fine.

So, does anyone happen know or have any idea what the optimum/ideal DO saturation is? The ideal number on wished for on the DO Meter that guarantees/insures a safe oxygenated environment for all the plants plus all the microbe colonies in RDWC’s?

9.1mg/l I forget the conversion to ppm.

Question: If you test the DO Sat with a DO meter and discover you do have a serious low oxygen problem in your water, how do to fix this low oxygen problem in your water? Are do you do nothing and hope the problem simply fixes itself before everything wilts and dies or becomes diseased and dies….

If you are using any of the standard aeration tools sold nowadays you are unlikely to run into that issue.

xygen analyzers and DO meters are always available for precise oxygen measurement that eliminates the hoping, guessing if there is really enough oxygen to sustain a healthy environment.

If you have those test your water & post your setup/results....I'd love to see them.

Here is what I'm currently doing...(my setup)

Right now, I have two of these.... (it's massive amounts of air, I can run my nail guns with it)


One of them I've split the output, to run two of these in the res. These things are awesome. They infuse the water with air...tiny bubbles. If I remove these from the system, the metabolism goes way down. I've noticed this because they are on a circuit that often trips. So, I've had many occasions where I look & the plants aren't eating as much. Then I realize it's because that pump is off. I'm aerating every bucket, the control bucket, & the res, & I think they would still benefit from more.


The other runs 16 of these in the buckets.
http://hydrobuilder.com/air-stone-6-15cm-case-of-12.html

Then I have two of these...
http://hydrobuilder.com/air-pump-with-2-outlets-7-8-lt-per-minute.html

Which runs two of these (each air pump is T'd to make a single feed) in the control bucket.
http://www.amazon.com/dp/B00VT3MSXY

The above air "stones" are much better than standard air stones in my opinion. The Aqua Lungs are the best of the best, but they take up so much room.

 

[J Henry]

"Problem" is not the word I would use. But I think a lot of hydro growers are not getting maximum results. I have yet to reach a point where the water is too oxygenated.

Here is a chart. But basically, at the temps we operate the water at, at sea level, 9.1mg/ml is saturation point.
http://www.hakkoairpumps.com/subcat15.html

I'll tack my aeration setup at the bottom if you care to see how far I have gone, & I think it would benefit from more.

But to get back to it....I have a lot of oxygen....a lot...& I think if I were to add more it would be even better. Perhaps soon I would reach saturation levels of possible O2 in the water, but the infusion method would need to be updated. Meaning, Aqua lungs, do a much better job of dissolving the water, but I can't afford to run those in every bucket. Aside from the fact that they are so large. So, I think you could reach "possible saturation" points....but it would be quite expensive to get all that air infused into the water. Standard air stones don't do a good job of it.

So, I guess what I'm saying (I'm sorry, I'm waking up slowly today) is you could have enough air pumps to achieve maximum O2, but you would need to get that infused/dissolved into the solution, which standard air stones do very poorly.

They, are absolutely right. From what I've seen, you can't achieve too much DO. Though I've not measured mine, just going from observing the plants.

Yes, they mean plenty of DO, lots of it.

At the temps we operate the water at, seal level, optimal barometric pressure, no salt, 100% saturation = 9.1 mg/l

Here are two sites to give you an idea of what you are driving at. If you aren't going to read all of it, some basics are:
The atmosphere can hold different amounts of water vapor (humidity) depending on the temperature. That's why it's called relative humidity. The hotter the air, the more water it can hold. You probably know all that already.
Water is much the same, but reversed. Water can hold different amounts of O2 depending on the temp of the water. But the colder the water, the more DO it can hold. Salinity also has an effect, sea level, atmospheric pressure. You need to be above 5mg/l for average marine plants. Cannabis though, is not a natural marine plant. From what I've seen it will take all the DO you can throw at it.

http://water.usgs.gov/edu/dissolvedoxygen.html



100% is ideal
http://fivecreeks.org/monitor/do.shtml

That's because it's much lower than what the plant needs. So if the plant is doing ok, the microbes should be ok.

Considerable isn't the word I would use. Billions of them are invisible to the naked eye. But they are also creating oxygen as they do their thing. So, if you have any amount of quality aeration, they should be fine.

9.1mg/l I forget the conversion to ppm.

If you are using any of the standard aeration tools sold nowadays you are unlikely to run into that issue.

If you have those test your water & post your setup/results....I'd love to see them.

Here is what I'm currently doing...(my setup)

Right now, I have two of these.... (it's massive amounts of air, I can run my nail guns with it)


One of them I've split the output, to run two of these in the res. These things are awesome. They infuse the water with air...tiny bubbles. If I remove these from the system, the metabolism goes way down. I've noticed this because they are on a circuit that often trips. So, I've had many occasions where I look & the plants aren't eating as much. Then I realize it's because that pump is off. I'm aerating every bucket, the control bucket, & the res, & I think they would still benefit from more.


The other runs 16 of these in the buckets.
http://hydrobuilder.com/air-stone-6-15cm-case-of-12.html

Then I have two of these...
http://hydrobuilder.com/air-pump-with-2-outlets-7-8-lt-per-minute.html

Which runs two of these (each air pump is T'd to make a single feed) in the control bucket.
http://www.amazon.com/dp/B00VT3MSXY

The above air "stones" are much better than standard air stones in my opinion. The Aqua Lungs are the best of the best, but they take up so much room.

 

[J Henry]

Thanks Junk,
That’s some detailed information. I appreciate you spending your time provide such detailed info. Just finished reading your post and will follow up and get back with you.
Just thinking and wondering out loud a moment before I start digesting you post.
Why do most people say the water temperature should be maintained between 65-69 F?
Is there any real scientific basis or reason to maintain this cooler water temp range? Why, for what reason?
Physiologically, that cool water temperature could causes lower/less efficient plant metabolism resulting in slower growth, longer growing periods, longer time to reach harvest and weeks longer get fruit to market.
Plant metabolism is higher if the water temp was higher, 80 F or so. Plant grow quicker, matures quicker, get more fruit to market sooner, greater net profit and so on. 80 F water temp, great light, air circulation @ 72 F controlled air temp seems perfect grow conditions to me.
Is the reason for chilling water because if the water temp is maintained at this cooler temp, the cooler water theoretically can hold a little more DO at saturation than warmer water at 70-80F….
Is all this hubbub, effort and cost simply to keep the water temp between 65 – 69F about the oxygenation? Or, is the cool water temp about just about the plants comfortable? Or is it something else completely different than oxygenation and keeping plants cool and comfort?
Thanks
J

 

[organix4207]

my little dwc experience says to keep the temp between 65-69 for maximum oxygen saturation and to combat pithium , root slime etc .

 

[mojavegreen]

And exactly how much oxygen does a plant absorb through its roots? What is the rate of absorption?

 

[J Henry]

Thanks organix4207 - Fungi usually thrive in low to little oxygen environments and fail to thrive in oxygen-rich environments. Do you think the fungi could grow at warmer water temps and thieve if the water was maintained at 100% DO saturated or even up to 140% DO supersaturated?


Mo – need root doctor for those 2 questions.

 

[40BRIX]

oxygen in the h2o is used locally by the roots for cellular respiration, for the process of active transportation of the highly mineralized nutrient solution. Higher osmotic concentrations in the nutrient solutions will usually require active transport, although I'm sure there's some passive transport just due to the volume of water. There have been no demonstrated benefits in research showing higher DO helps the plants. Super saturated DO solutions have been shown to be detrimental.
Root fungi will form a symbiotic relationship, attaching physically to the roots and assisting with the active transport, offloading some work from the plant roots. I prefer sterile solutions, no bugs for me!
Increasing transpiration through the plant also helps get the water and nutrients into the plant, so reduce humidity in the room, increase temp difference between water and air, increase air movement in the room.

 

[Junk]

Super saturated DO solutions have been shown to be detrimental.
Root fungi will form a symbiotic relationship, attaching physically to the roots and assisting with the active transport, offloading some work from the plant roots. I prefer sterile solutions, no bugs for me!

According to those sites I posted anything over 100% DO is detrimental...

How you achieve 120-140% DO is beyond me.

 

[J Henry]

Junk, sustain 100% DO Saturation continuous seem reasonable and healthy to me too, Much better than intermittent low oxygen crisis from time to time.

How do you manipulate DO Super-Saturation greater than 100% is a good question: Applying this chemistry gas law...
Henry's Law - https://en.wikipedia.org/wiki/Henry's_law