c02

[legallyflying]

Yo smokerator,
While no, you obviously dont NEED to have a ppm controller but if your using tanks, you will probably save that money in CO2 in a year if you did. While you use pens and test co2 levels, I highly doubt that most people just throwing fermenting goo in their room or putting a timer on the co2 tanks are.

Your right about any increase over ambient is a good thing as co2 is the most limiting factor in most situations. I'm kind of anal in terms of room control and knowing what is going on in there and how plants are reacting. The amount of notes I take are borderline manic but then again I dont typically suffer nutrient deficencies, burn plants, or realize low yields. I also vary my co2 levels depending on growth and flower phase. Not that the plants would suffer from higher amounts (except in weeks 3-6 of flower) but from the reading I have done, high levels (1500+) in other stages is somewhat of a waste.

At any rate, do anything you want to in your own grow room. What you choose to do is really a question of your goals and financial resources. I recently installed a tankless water heater in my flower room to produce CO2 in the cheapest fashion and I'm quite happy with it.

 

[Wolverine97]

Yo smokerator,
While no, you obviously dont NEED to have a ppm controller but if your using tanks, you will probably save that money in CO2 in a year if you did. While you use pens and test co2 levels, I highly doubt that most people just throwing fermenting goo in their room or putting a timer on the co2 tanks are.

Your right about any increase over ambient is a good thing as co2 is the most limiting factor in most situations. I'm kind of anal in terms of room control and knowing what is going on in there and how plants are reacting. The amount of notes I take are borderline manic but then again I dont typically suffer nutrient deficencies, burn plants, or realize low yields. I also vary my co2 levels depending on growth and flower phase. Not that the plants would suffer from higher amounts (except in weeks 3-6 of flower) but from the reading I have done, high levels (1500+) in other stages is somewhat of a waste.

At any rate, do anything you want to in your own grow room. What you choose to do is really a question of your goals and financial resources. I recently installed a tankless water heater in my flower room to produce CO2 in the cheapest fashion and I'm quite happy with it.

Not only is 1500ppm a waste for a lot of the growth phase, there's new research which suggests that when you keep them at those kind of levels the plants develop sort of a dependence on high levels. The evidence showed that if plants were grown throughout veg and early flower with high co2 and then reduced to below 800ppm growth virtually stopped. I run mine around 800 during veg, bump to 1000 during early flower, 1200 during peak bloom and then back down to 600-700 for the final two weeks.

I'm curious why you say you reduce levels through weeks 3-6 of flower, as that's when mine are at their highest. I've always read that you want to lower your levels the last 2-3 weeks as it can affect thc production.

 

[legallyflying]

I wrote what I was thinking incorrectly. The only time I really crank the Co2 is in weeks 3-6. Sometimes during the stretch as well depending on how the SCROG is filling out.

I read about plants becoming co2 dependent over several generations, but never in a single gen. Do you remember where you read this?

 

[Wolverine97]

I wrote what I was thinking incorrectly. The only time I really crank the Co2 is in weeks 3-6. Sometimes during the stretch as well depending on how the SCROG is filling out.

I read about plants becoming co2 dependent over several generations, but never in a single gen. Do you remember where you read this?

It was either Maximum Yield or Urban Gardener.

 

[Wolverine97]

So far I haven't found it, but the following is a very good read, lots of detail. I'll look through my hard copies and see if I can find it.
http://www.maximumyield.com/article_sh_db.php?articleID=283

 

[legallyflying]

I think I know the article your referencing I'll try and look through my teetering stack of urban gardner and max yield magazines. I did find this though which makes a pretty strong case for high co2 (for those less in the know about plant processes, they were testing the effects on RESPIRATION i.e. what happens when the lights are off):

Rather than assessing plants grown in chambers in a greenhouse, as most studies have done, Leakey's team made use of the Soybean Free Air Concentration Enrichment (Soy FACE) facility at Illinois. This open-air research lab can expose a soybean field to a variety of atmospheric CO2 levels – without isolating the plants from other environmental influences, such as rainfall, sunlight and insects.
Some of the plants were exposed to atmospheric CO2 levels of 550 parts per million (ppm), the level predicted for the year 2050 if current trends continue. These were compared to plants grown at ambient CO2 levels (380 ppm).
The results were striking. At least 90 different genes coding the majority of enzymes in the cascade of chemical reactions that govern respiration were switched on (expressed) at higher levels in the soybeans grown at high CO2 levels. This explained how the plants were able to use the increased supply of sugars from stimulated photosynthesis under high CO2 conditions to produce energy, Leakey said. The rate of respiration increased 37 percent at the elevated CO2 levels.
The enhanced respiration is likely to support greater transport of sugars from leaves to other growing parts of the plant, including the seeds, Leakey said.
"The expression of over 600 genes was altered by elevated CO2 in total, which will help us to understand how the response is regulated and also hopefully produce crops that will perform better in the future," he said.
Leakey is also an affiliate of the Institute for Genomic Biology at Illinois.

 

[Wolverine97]

I think I know the article your referencing I'll try and look through my teetering stack of urban gardner and max yield magazines. I did find this though which makes a pretty strong case for high co2 (for those less in the know about plant processes, they were testing the effects on RESPIRATION i.e. what happens when the lights are off):

Rather than assessing plants grown in chambers in a greenhouse, as most studies have done, Leakey's team made use of the Soybean Free Air Concentration Enrichment (Soy FACE) facility at Illinois. This open-air research lab can expose a soybean field to a variety of atmospheric CO2 levels – without isolating the plants from other environmental influences, such as rainfall, sunlight and insects.
Some of the plants were exposed to atmospheric CO2 levels of 550 parts per million (ppm), the level predicted for the year 2050 if current trends continue. These were compared to plants grown at ambient CO2 levels (380 ppm).
The results were striking. At least 90 different genes coding the majority of enzymes in the cascade of chemical reactions that govern respiration were switched on (expressed) at higher levels in the soybeans grown at high CO2 levels. This explained how the plants were able to use the increased supply of sugars from stimulated photosynthesis under high CO2 conditions to produce energy, Leakey said. The rate of respiration increased 37 percent at the elevated CO2 levels.
The enhanced respiration is likely to support greater transport of sugars from leaves to other growing parts of the plant, including the seeds, Leakey said.
"The expression of over 600 genes was altered by elevated CO2 in total, which will help us to understand how the response is regulated and also hopefully produce crops that will perform better in the future," he said.
Leakey is also an affiliate of the Institute for Genomic Biology at Illinois.

Oh yeah, for sure elevated levels, yes yes yes. I should have been more clear. What they were saying was that sustained levels over 1200ppm created dependency in the test plants, but only if levels were dropped below the 7-800ppm threshold. It said that increasing levels to around 1000ppm saw the most efficient use of supplementation, and the plants didn't hit a wall when dropped down to ambient levels.

That was an extremely condensed version of what was said. It was a fairly recent issue, I'd say in the last six months. I haven't had time to look yet, it's the misses' birthday.