Co2 Enrichment

[Homesteader]

Whats you way of doing this? Do you just make a big 50 gallon batch and set it cook on the side?
For how long will it produce this amount of co2?
It really depends on your mix and whether you have right ratios but I think at least 50 gallons per plant can give you enough, but the larger the size the easier the humidity is to control.
If you go living organic soil for your pots, would it also produce this amount or at least keep it around 400-500 in a sealed environment without a heap of soil cooking on the side?
Exactly, you don't want it producing a ton of other gasses so having a mix high in Nitrogen will give off too much ammonia or it will stunt plants.
Why do you need new mix everytime? Do you mean starting from scratch or just replenishing your depleted living soil with amendments and let it cook again?
I never am able to achieve the same by just replenishing. I assume the Carbon/Nitrogen/Phos ratio is most important and once the microbes live and die the soil because to drained of that ratio, as they become SOM. I grow for myself, so I don't exactly care about the optimum and maximum production but think this method could be used to cut down cost at least for someone with the ability to hold the gas.

Also how high does your rh climb in a setup like this?
Mine ussually is around 60rh unti but that depends on you soil mix. Peat holds moisture well for me and coco lets thing breath by creating air pockets. You have to find the in between depending on what amendment you are using though.

I don’t have co2 meter or a bottle, instead i got questions brah :)

You would definitely want to monitor it with a sealed room, at least until you can get your mix right.

 

[crimsonecho]

Whats you way of doing this? Do you just make a big 50 gallon batch and set it cook on the side?
For how long will it produce this amount of co2?
It really depends on your mix and whether you have right ratios but I think at least 50 gallons per plant can give you enough, but the larger the size the easier the humidity is to control.
If you go living organic soil for your pots, would it also produce this amount or at least keep it around 400-500 in a sealed environment without a heap of soil cooking on the side?
Exactly, you don't want it producing a ton of other gasses so having a mix high in Nitrogen will give off too much ammonia or it will stunt plants.
Why do you need new mix everytime? Do you mean starting from scratch or just replenishing your depleted living soil with amendments and let it cook again?
I never am able to achieve the same by just replenishing. I assume the Carbon/Nitrogen/Phos ratio is most important and once the microbes live and die the soil because to drained of that ratio, as they become SOM. I grow for myself, so I don't exactly care about the optimum and maximum production but think this method could be used to cut down cost at least for someone with the ability to hold the gas.

Also how high does your rh climb in a setup like this?
Mine ussually is around 60rh unti but that depends on you soil mix. Peat holds moisture well for me and coco lets thing breath by creating air pockets. You have to find the in between depending on what amendment you are using though.

I don’t have co2 meter or a bottle, instead i got questions brah :)

You would definitely want to monitor it with a sealed room, at least until you can get your mix right.

Thanks for the info dude.
I’m actually not crazy about 1000ppm either. I’m a personal grower like you. Its just that my room which houses the tent is not very well ventilated and the temps are a bit low at the moment so i have to keep the doors closed and recirculate the air inside. Its not sealed and there are tons of places like tiny gaps between wall panels and under the doors etc. where the gas exchange could occur. But i doubt that it could hold it at the required ppms like 400 because there are many plants inside. I also just started a 10 litre fermantation with yeast and sugar to provide a little boost and i’m just trying to broaden my horizons when it comes to co2 supplementation.

 

[3 balls]

I'm my experience Co2 does benefit from higher temps. I am not an expert on Co2 by any means, but everyone I know who uses it runs their garden on the warm side specifically to increase plant metabolism and transpiration, since the plant can use more nutrients with an increase in Co2.

I do know for sure it's used with high temps in greenhouses. Sometimes really high temps. Where without added Co2 the plants would suffer big time.

When I first started using CO2 I read some bad information that higher temps were essential to get the full effect of enrichment. You can research that this is false. The confusion comes in to play as CO2 will in fact reduce stress in higher than ideal temps. In other words, whatever temps suit your genetics best should be the same with or without enrichment. If at times your cooling is unable to keep up, enrichment will help but IMO boosting your VPD will help more.

 

[Dirtbag]

When I first started using CO2 I read some bad information that higher temps were essential to get the full effect of enrichment. You can research that this is false. The confusion comes in to play as CO2 will in fact reduce stress in higher than ideal temps. In other words, whatever temps suit your genetics best should be the same with or without enrichment. If at times your cooling is unable to keep up, enrichment will help but IMO boosting your VPD will help more.

Good to know, thanks for that.

 

[Homesteader]

When I first started using CO2 I read some bad information that higher temps were essential to get the full effect of enrichment. You can research that this is false. .

It is not bad information or false. The stomata open fully at higher temps. if you are running a co2 enriched grow with high intensity light but grow in colder temps, that will be your limiting factor because the stoma will not be fully open and the plant doesn't exchange the gas efficiently. It is strain dependent though, and then water usage becomes the next limiting factor and how much can you keep up with the plant drinking.

 

[3 balls]

It is not bad information or false. The stomata open fully at higher temps. if you are running a co2 enriched grow with high intensity light but grow in colder temps, that will be your limiting factor because the stoma will not be fully open and the plant doesn't exchange the gas efficiently. It is strain dependent though, and then water usage becomes the next limiting factor and how much can you keep up with the plant drinking.

Temperature is obviously relative. I did not suggest cold temps. Purposely setting your temps at 90+ is a common suggestion that I have seen and is what I was referring to. The research I've read does not support this. I believe you misinterpreted what I was saying. You are one of the smarter scientific types on here so now I'm curious, allowing for strain variations, what would you recommend as an average temp in a CO2 enriched environment?

 

[Ikkt]

Just looked into some papers, there's even one concerning these matter specifically on cannabis ("high yielding Mexican variety", S. Chandra et al). The stomatal conductance is higher at 30° than at 20, but not so much. But it decreases very sharply from 30 to 35 degree.
So as far as you're only considering stomatal conductance, without the means to measure it, I think it's better to stay at a little lower temp than to get too high.
One or two degrees too much seem to have a profound negative effect on s.c., dropping it much more than one or two degree less than ideal.
And considering the spot heating effect of HID lighting I think it's probably better to stay around 25° degree than around 30°. (68°F ≈ 20°C, 86°F ≈ 30°C. just realized I had it wrong, thought 80f = 30c, but it's 27c so it's probably quite ideal to be at 80f max.)

I also had the impression that to match PPFD = ppm CO2 is about ideal, but have to think and look into it further. Though not for max. yield but for max. efficiency.

 

[Ikkt]

Just looked into some papers, there's even one concerning these matter specifically on cannabis ("high yielding Mexican variety", S. Chandra et al). The stomatal conductance is higher at 30° than at 20, but not so much. But it decreases very sharply from 30 to 35 degree.
So as far as you're only considering stomatal conductance, without the means to measure it, I think it's better to stay at a little lower temp than to get too high.
One or two degrees too much seem to have a profound negative effect on s.c., dropping it much more than one or two degree less than ideal.
And considering the spot heating effect of HID lighting I think it's probably better to stay around 25° degree than around 30°. (68°F ≈ 20°C, 86°F ≈ 30°C. just realized I had it wrong, thought 80f = 30c, but it's 27c so it's probably quite ideal to be at 80f max.)

I also had the impression that to match PPFD = ppm CO2 is about ideal, but have to think and look into it further. Though not for max. yield but for max. efficiency.

So, looked at the Chandra data again.
Stomatal conductance doesn't correlate with net photosynthesis, doesn't seem to be as big a factor as one would think.
Perhaps lower temps have overall benefit, I often had the impression that people only need to run that hot to get transpiration up cause they're hesitant to run the EC as high as some of the Dutch folks, tomato people etc. do.
They're often at or even fairly above 3!

I'll have to take another more thorough look at the data and additional studies with other plants next week though. Not really sure about all this yet.

(Some time ago I had plants, even cacti, in salty media with a run off EC of more than 10 and they were quite healthy. But they had a lot of time to get used to it, at least 5-10years. It's rapid fluctuations not the value thats most problematic, at least to some extent, I think. Flushing the cacti killed 2 out of 3...)

 

[3 balls]

Just looked into some papers, there's even one concerning these matter specifically on cannabis ("high yielding Mexican variety", S. Chandra et al). The stomatal conductance is higher at 30° than at 20, but not so much. But it decreases very sharply from 30 to 35 degree.
So as far as you're only considering stomatal conductance, without the means to measure it, I think it's better to stay at a little lower temp than to get too high.
One or two degrees too much seem to have a profound negative effect on s.c., dropping it much more than one or two degree less than ideal.
And considering the spot heating effect of HID lighting I think it's probably better to stay around 25° degree than around 30°. (68°F ≈ 20°C, 86°F ≈ 30°C. just realized I had it wrong, thought 80f = 30c, but it's 27c so it's probably quite ideal to be at 80f max.)

I also had the impression that to match PPFD = ppm CO2 is about ideal, but have to think and look into it further. Though not for max. yield but for max. efficiency.

That is the research I was referring to!! Thanks
I'm no scientist and I don't understand all of it but between that paper and personal experience I call bullshit on this sort of information:
You should maintain high temperatures, between 85°F (30°C) and 95°F (35°C).

When you’re adding CO2, especially higher amounts, you will get the best results at higher temperatures.

Normally you want your garden to be a comfortable room temperature, but when adding CO2 at very high levels, you want to keep temps above 85°F (30°C).

Many growers recommend you keep temps as high as 95°F (35°C) when maintaining CO2 levels around 1200-1500 PPM.

If the temperature is lower than 85°F (30°C), you won’t seeas much benefit from adding CO2.

However, since you must seal your grow room to keep all the CO2 from escaping, it'll likely be easy to keep temps that high when you're running your grow lights.

For growers supplementing smaller amounts of CO2, it isn't recommended that you specifically try to raise the temperature of your grow space, but the CO2 can help protect your plants from heat and light stress.

No matter what, watch plants closely for signs of heat stress and react accordingly!

 

[Kot]

That is the research I was referring to!! Thanks
I'm no scientist and I don't understand all of it but between that paper and personal experience I call bullshit on this sort of information:
You should maintain high temperatures, between 85°F (30°C) and 95°F (35°C).

When you’re adding CO2, especially higher amounts, you will get the best results at higher temperatures.

Normally you want your garden to be a comfortable room temperature, but when adding CO2 at very high levels, you want to keep temps above 85°F (30°C).

Many growers recommend you keep temps as high as 95°F (35°C) when maintaining CO2 levels around 1200-1500 PPM.

If the temperature is lower than 85°F (30°C), you won’t seeas much benefit from adding CO2.

However, since you must seal your grow room to keep all the CO2 from escaping, it'll likely be easy to keep temps that high when you're running your grow lights.

For growers supplementing smaller amounts of CO2, it isn't recommended that you specifically try to raise the temperature of your grow space, but the CO2 can help protect your plants from heat and light stress.

No matter what, watch plants closely for signs of heat stress and react accordingly!

This is just from one website. Never seen such recommendations on other sites. 80 degrees is the sweet spot imho.

 

[dorjewright]

My first time running C02 this past Fall I let temps rise to 85f. Also got a few hermies I think from the royal purple kush cbd. Seeded the whole garden. I've had plants hermi before but late in flower and never got more than a scattering of seeds. But the sealed room I think kept the pollen circulating around the room. Without co2 and venting the pollen got sucked out.
This time I will go with 80f and co2 only through the stretch and maybe a little longer. Growing just a few plants this time so I will be able to inspect them more carefully.

 

[3 balls]

This is just from one website. Never seen such recommendations on other sites. 80 degrees is the sweet spot imho.

Not sure what the first part has to do with anything but I agree 80F is right about perfect.

 

[Homesteader]

Purposely setting your temps at 90+ is a common suggestion that I have seen and is what I was referring to.

I didn't realize people were suggesting that high of a temp. I like my temps to be between 80 and 85 until the last few weeks of flower.

 

[3 balls]

I didn't realize people were suggesting that high of a temp. I like my temps to be between 80 and 85 until the last few weeks of flower.

I wouldn't mind creeping closer to 85 and saving on AC costs but I worry about the temp swing at lights out. Do you think 65/85 is a safe range if the RH spikes can be controlled?