Cannabis and o2 in the rootzone

[Observer]

It's all about pressure and temperature.


The article pertains to greenhouse growing, so I suspect the use of O3 might be more appealing to large-scale, commercial greenhouse growing operations that have lots of $$$ to spend on the required equipment. It certainly wouldn't apply to a simple organic soil grower like me.

I'm wondering if a simple aquarium air pump would work to add atmospheric O2 to my irrigation water. Would something like this help to increase the DO?

View attachment 11695

You just need to bubble the surface water

 

[Aqua Man]

You just need to bubble the surface water

Kinda and need some water mixing so if an airstone is at the bottom it will provide both

 

[Rootsruler]

Kinda and need some water mixing so if an airstone is at the bottom it will provide both

Would a small solar fountain in the res dissolve oxygen as efficiently as an airstone?

 

[Aqua Man]

Would a small solar fountain in the res dissolve oxygen as efficiently as an airstone?

It all depends on the load (how much is being used). The bubbles dont provide o2 its the surface agitation. There is not enough dwell time or pressure for bubbles to do much other than create surface agitation.

 

[Observer]

It all depends on the load (how much is being used). The bubbles dont provide o2 its the surface agitation. There is not enough dwell time or pressure for bubbles to do much other than create surface agitation.

Yea

That paper stated the more the better and the smaller bubbles, sink down more supposedly allowing more o2/atmosphere mixture and surface area & what not.

 

[Aqua Man]

Yea

That paper stated the more the better and the smaller bubbles, sink down more supposedly allowing more o2/atmosphere mixture and surface area & what not.

Kinda but only to equilibrium honestly bubble size has a lot to do with surface agitation and i do agree smaller is better. But the bubbles in the water lack the pressure needed to force o2 into the water. O2 is also a hard gas to dissolve in water much much much more so than co2 and i have a LOT of experience doing that. I can tell you that supersaturation of o2 is extremely difficult to achieve and maintain.

The microbubbles that some of this tech uses tricks DO sensors into counting bubbles as dissolved and that just not the case.

The only really effective way for our use is to create an o2 rich area above the water. Extremely effective for fogponics because the surface area to water volume ratio is extremely high and even more so with aeroponics.

For soil and peat it will need to be pushed into the media and hydro good mixing with a high o2 level at the water surface

 

[Amnesia]

What kinda water temps are you giving them?

Room temperature. The air temperature is 76º in the room. I usually fill my watering cans after each use. So, they sit for two or more days before the water is used.

Kinda and need some water mixing so if an airstone is at the bottom it will provide both

That's what I was thinking. The article said that smaller bubbles are better, so that would call for an air stone. Contact time might matter, too, so I was thinking of a long, vertical tube with an air stone at the bottom. I'd probably start with some air stones in the watering cans, though.

 

[Observer]

Kinda but only to equilibrium honestly bubble size has a lot to do with surface agitation and i do agree smaller is better. But the bubbles in the water lack the pressure needed to force o2 into the water. O2 is also a hard gas to dissolve in water much much much more so than co2 and i have a LOT of experience doing that. I can tell you that supersaturation of o2 is extremely difficult to achieve and maintain.

The microbubbles that some of this tech uses tricks DO sensors into counting bubbles as dissolved and that just not the case.

The only really effective way for our use is to create an o2 rich area above the water. Extremely effective for fogponics because the surface area to water volume ratio is extremely high and even more so with aeroponics.

For soil and peat it will need to be pushed into the media and hydro good mixing with a high o2 level at the water surface

Thanks Aquaman

 

[Observer]

@Aqua
@Moe.Red

have either of you played with Liquid oxygen?

it seems expensive and probably not worth it, best method probably is the o2 concentrator.....or oxygen gas tanks but that has its risk.

thought id ask.

 

[Aqua Man]

@Aqua
@Moe.Red

have either of you played with Liquid oxygen?

it seems expensive and probably not worth it, best method probably is the o2 concentrator.....or oxygen gas tanks but that has its risk.

thought id ask.

Whacha mean by liquid o2?

 

[moe.red]

I think there are 2 kinds of liquid O2.

There are gels that deep sea divers use - never seen one up close.
There is liquid O2 - frozen in bottles.

I have not looked into either one. I can't imagine the cost and safety as well as the equipment needed to use this is worth it for cannabis. Maybe in space.

 

[Pipecarver]

Well i have this idea that using fabric pots in a pail with an airstone or o2 concentrator underneath will greatly improve your gas exchange and o2 levels. A rack would be placed in the pail to set the bags on and the lips of the bags folded over the rim of the pail so the air pump s in will be forced into the media and vent through the soil. This would best be done with a breathable media like peat or coco with perlite

Could you use clay balls on the bottom to cover a net pot and air stone with a line up the inside of the fabric pot. a light mix of 50/50 perlite soil/coco?

 

[Amnesia]

Could you use clay balls on the bottom to cover a net pot and air stone with a line up the inside of the fabric pot. a light mix of 50/50 perlite soil/coco?

I had similar thoughts. It seems the delivery mechanism isn't as big a challenge as the source of the oxygen.

 

[Aqua Man]

Could you use clay balls on the bottom to cover a net pot and air stone with a line up the inside of the fabric pot. a light mix of 50/50 perlite soil/coco?

You probably could but need to watch the media and flow of air as to not dry it out to fast

 

[Pipecarver]

You probably could but need to watch the media and flow of air as to not dry it out to fast

yes, that maybe why they can be used in the auto pots with water available 24/7. Probably not good to dry out the roots first then, with air drying from the bottom up....

 

[Aqua Man]

yes, that maybe why they can be used in the auto pots with water available 24/7. Probably not good to dry out the roots first then, with air drying from the bottom up....

Yeah you can do that by regulating the flow. It wont take much to really improve the gas exchange. There are several way to accomplish this and if you want to try i can give you my thoughts on a few if you like

 

[Pipecarver]

hey, thanks but don't go to any extra work on it. I'm using air in the auto pots and it may have been my mix that gave me different results. 2 pots may have had too heavy a mix, not allowing the air up into the root zone. I've a much lighter mix this time around and i was careful at how many clay balls were laid down , I just covered the net pots/domes then the lighter mix all around....

If I can control the Humidity, i'm sticking with the new pots. I like the ease of feed and the overall health in the plants.

 

[Max 2]

I used to spend 30 min in my sealed room and the ppm would go from the setpoint of 1200ppm to 2400ppm. Overnight it could reach as high as almost 3k but once the lights came on it wasn’t 30 min before the tank was kicking back on. Alot of variables there but yeah

B good to know your oxygen levels overnight.when your not exchanging for fresh oxygen.do you think plant would benefit from that.just overnight and shutting back off through the day.

 

[Aqua Man]

B good to know your oxygen levels overnight.when your not exchanging for fresh oxygen.do you think plant would benefit from that.

It’s beneficial 24hrs a day unlike co2 in the atmosphere is only beneficial during lights on

 

[Anthem275]

It’s beneficial 24hrs a day unlike co2 in the atmosphere is only beneficial during lights on

How should I do it in a flood and drain setup?

 

[Max 2]

It’s beneficial 24hrs a day unlike co2 in the atmosphere is only beneficial during lights on

I see now..I just woke up to myself lol..

 

[moe.red]

How should I do it in a flood and drain setup?

You could super oxygenate the water prior to flooding, but unless the root zone is sealed up I'll bet it is not worth the effort or expense. Would need testing.

 

[Anthem275]

You could super oxygenate the water prior to flooding, but unless the root zone is sealed up I'll bet it is not worth the effort or expense. Would need testing.

I do not know and as you stated would need testing. I have started screwing around with different media, as in one that holds more water below the root zone and a more porous product above the root zone.

 

[Aqua Man]

Yeah about the only way i see is to cover the table with plastic or styrofoam with cut outs for the pots…. Then pump in o2 from the concentrator on the furthest end from the drain

 

[Observer]

I think there are 2 kinds of liquid O2.

There are gels that deep sea divers use - never seen one up close.
There is liquid O2 - frozen in bottles.

I have not looked into either one. I can't imagine the cost and safety as well as the equipment needed to use this is worth it for cannabis. Maybe in space.

correct.

 

[Observer]

Whacha mean by liquid o2?

Amazon.com

 

[Aqua Man]

Amazon.com

Cannabis marketing 101 at its finest… take something factual and find a way to twist it and scam people out of their money.

See a big part of the problem is the majority of ppl who use products and don’t have issue with them seem to support them and say they work. The problem is the fact that they don’t hurt your plants doesn’t equate to they help your plants…. This is almost exclusively what drives all of this marketing gimmickry as all these companies know this

 

[Observer]

Cannabis marketing 101 at its finest… take something factual and find a way to twist it and scam people out of their money.

See a big part of the problem is the majority of ppl who use products and don’t have issue with them seem to support them and say they work. The problem is the fact that they don’t hurt your plants doesn’t equate to they help your plants…. This is almost exclusively what drives all of this marketing gimmickry as all these companies know this

yea i was trying to find the LIquid oxygen i was looking at last night, some of these are just peroxide lol

 

[Aqua Man]

yea i was trying to find the LIquid oxygen i was looking at last night, some of these are just peroxide lol

Short of controlling the atmosphere above the water…. Nothing will help imo

 

[Observer]

Short of controlling the atmosphere above the water…. Nothing will help imo

Yeah there don't seem to be a lot of possible solutionsz I've been racking my head about DO

 

[Aqua Man]

Yeah there don't seem to be a lot of possible solutionsz I've been racking my head about DO

Been there bro… like months upon months of it

 

[moe.red]

Been there bro… like months upon months of it

Not me.

Born with it.

 

[Franksta]

@Aqua Man - Sorry I didn't get back to this sooner.


Well... I'm going to have to eat my words on that one. I'm sure I saw it somewhere, but I sure can't find it now. If I eventually find it, I'll try to remember to let you know. It's probably wrong, though, because if it were correct there would be more information, and there isn't any.

It's become clear to me that O2 has understated importance. This document was helpful to me as a primer on the subject:

http://www.dramm.com/media/Dissolved%20Oxygen%20in%20the%20Greenhouse.pdf

As a soil grower, I'm mostly interested in finding ways to increase O2 in the soil. That's why @Pipecarver's post with the air domes interested me. I don't know how many things I'm doing wrong, but how I prepare irrigation water might be one of them. I've been filling my watering cans after I use them and letting them sit till the next watering. Now I'm thinking that doing so makes the water anaerobic, both from off-gassing and warming the water to room temperature. That takes me in the direction of wondering how to improve soil oxygenation.

Meanwhile... I see that you're also correct about how H2O2 is best used as a disinfectant. I found recipes for using it to get rid of fungus gnats and used one of them yesterday. It's a 4:1 mix of water to 3% hydrogen peroxide. I sprayed it on the surface of the soil and today I haven't seen any gnats. Hooray for that!

Keep in mind water too cold although it's going to have lots of oxygen it can shock the plants. Will take hours to recover and might be an issue with frequent watering cycles

Cold sequester of oxygen is most helpful in a specific range IMO


I'm not sure if @Aqua Man has a specific optimal number he's dialed in or not. But I'm thinking it's between 60-65f or perhaps even a few degrees higher

 

[Aqua Man]

Keep in mind water too cold although it's going to have lots of oxygen it can shock the plants. Will take hours to recover and might be an issue with frequent watering cycles

Cold sequester of oxygen is most helpful in a specific range IMO


I'm not sure if @Aqua Man has a specific optimal number he's dialed in or not. But I'm thinking it's between 60-65f or perhaps even a few degrees higher.

With good gas exchange and at atmospheric o2 i found 72 to be the best for growth.

The reason for that is the metabolic increase from temperature provides more benefit than the small change in o2 at those temps.

Now if you start removing the limit of o2 based on temp…. I can see this being closer to 76-80f

 

[moe.red]

I’m running 78 in the fog res and roots and colonies explode.

I have been hotter by accident and I see diminishing returns past 80.

If running atmospheric O2 I have settled on 72 but have no data to support it is best. I run a chiller to maintain that.

 

[Amnesia]

I haven't checked the temperature of the water I'm using. I just fill the watering cans after each use, so they'll be ready when they're needed. I suspect the water temperature is in the mid to low 70s. The cans sit on the floor, which should be the coolest part of the room. The room itself is currently 76.8º and 51.2% RH.

 

[moe.red]

I haven't checked the temperature of the water I'm using. I just fill the watering cans after each use, so they'll be ready when they're needed. I suspect the water temperature is in the mid to low 70s. The cans sit on the floor, which should be the coolest part of the room. The room itself is currently 76.8º and 51.2% RH.

Everything I am talking about is hydro. I wouldn't expect the amount of O2 in water for soil or coco to make that much of a difference. I could be wrong on that, still lots of things to test.

 

[Amnesia]

Everything I am talking about is hydro. I wouldn't expect the amount of O2 in water for soil or coco to make that much of a difference. I could be wrong on that, still lots of things to test.

I thought it was about hydro, but I was quoted, so I thought maybe I was involved somehow. Otherwise, I think you're correct about the O2 in water not being a factor for an organic-soil-in-fabric-pot grower like me.

 

[moe.red]

I thought it was about hydro, but I was quoted, so I thought maybe I was involved somehow. Otherwise, I think you're correct about the O2 in water not being a factor for an organic-soil-in-fabric-pot grower like me.

Me too. Just started. I'm using tap water now. Not even PHing it. Weird.

All this O2 stuff doesn't make a lot of sense to me in soil. The medium is the limiting factor in getting O2 to the roots, so why choose it if you want to run O2? Makes no sense to me from an engineering standpoint.

 

[Amnesia]

Me too. Just started. I'm using tap water now. Not even PHing it. Weird.

I don't adjust the pH of my tap water. I test it just to know what it is. It is consistently 7.6. When I have done slurry tests on soil from my pots, however, it has been slightly below 6. As far as I know, the pH of the water I use hasn't impacted the health of my plants. I don't know that for sure, though.

All this O2 stuff doesn't make a lot of sense to me in soil. The medium is the limiting factor in getting O2 to the roots, so why choose it if you want to run O2? Makes no sense to me from an engineering standpoint.

I suppose a person could make a case for an O2 implementation for soil. The analysis probably would be better served by thinking of it as gas exchange, which is important for soil because roots do aerobic respiration. (Roots take in oxygen and give off carbon dioxide.) It's likely the use of gas permeable (e.g., fabric) pots with adequate air circulation is a satisfactory solution for most soil growers. (It's what I do.) Nevertheless, some of us want to explore better ways. So, the challenge would be to try to improve the movement of gases beyond what we already do. Ergo, in what ways could gas exchange processes be made more efficacious.