A c3 plant is a c3 plant. On a molecular level, how stomata take in co2, combine with a sugar with the help of an enzyme called RuBisco to make it a 3 carbon atom does not differentiate between wheat tomato or cannabis.

Wheat is not weed, and an african is not a Chinese person, does that mean they don't breathe the same or create energy differently?

Wow bro wrong again cannabis in recent studys has been and is classified as a c4 not a c3 proving my point entirely this won't let me share any links but look up cannabis as a minority c4 plant that was mistaken for c3 because of the photo period

KiLoEleMeNt said:

Wow bro wrong again cannabis in recent studys has been and is classified as a c4 not a c3 proving my point entirely

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Oh and your source only writes books on vegetables and tomatoes. Here's his website



So a tomato study is OK as long as it backs you up but not wheat

Post some direct links or.studies to your claims please

I am trying to post links but it won't let me past them or I would!!! refer to my last msg for something you can Google as for Howard being for vegetables I never said it wasn't ok to use the knowledge I said make sure you know about the exact plant you are referring to before stating facts about just one this is all I am going to discuss this with you as it is very rude to the OP and readers to continue as I said if u disagree that's fine you can disagree with me but the majority of all professional growers will agree with everything posted

So you can't even post links on a simple website yet everyone's supposed to listen to your horrid advice taken from a guy who wrote books on tomatoes.

BTW EVERY single plant your source has done studies on are c3 plants. So why are his c3 studies credible and others c3 studies are not? Not to mention non of his books so far mention anything about 1500 ppm co2 level as I'm skimming thru them.

Here's his book
http://www.amazon.com/Hydroponic-Tomatoes-Howard-M-Resh/dp/0931231973 On tomatoes, which is a c3 plant .

You sir, have not a.single fact or link or study to back any of your claims

Try looking at his actual books for his collage course sixth and seventh edition on the specific subject CO2 the missing ingredient
That out a shut u up

Carbon dioxide is an often-overlooked aspect of indoor gardening. It has been a hot topic as of late, and while plants can survive without it, even slight elevations of CO2 can greatly benefit a garden and lead to a higher sugar content in crops and greener plants.



There are many questions surrounding carbon dioxide’s effectiveness on improving plant health and increasing yields. I want to take a look at some of those questions and try to clarify a few things.

First and foremost, it is important to start a CO2 discussion with the most important biological function of a plant—photosynthesis. Without this chemical process, plants are unable to provide food for themselves. Many gardeners believe nutrients provide all the food a plant needs to develop. The truth is nutrients are not consumed as food. Nutrients contain minerals the plant uses in conjunction with light and CO2 during photosynthesis to produce the complex sugars it needs for energy and growth.

Leaves provide plants with food as they turn sunlight into food energy. Chlorophyll makes this energy transformation possible. Leaves also make the oxygen in the air that we breathe. Chlorophyll, a pigment found in the cells of leaves, is formed only in the presence of light and is what makes plants green. It is contained in the chloroplasts and has the ability to capture light energy. Sunlight shines through the top of the leaf and reaches the next layer of cells. The light energy is trapped by the chlorophyll in the chloroplasts, where a process that uses water changes the light energy into a kind of chemical energy. This chemical energy is stored in the chloroplasts and is used to make food.

Air enters the leaf through the stomata and moves into tiny spaces around the food-making cells in the leaf. CO2 from the air passes through the walls and membranes of the cells. CO2 enters the chloroplasts where the previously stored chemical energy converts the CO2 into sugar. Tubes in the plant carry the sugar from the leaf cells to other parts of the plant, such as roots, stems and flowers. Cells in these parts of the plant store some of that sugar.



Does CO2 help with clones and rooting?

An often-overlooked and under-studied aspect of plant responses to CO2 is the below-ground processes. When exposed to increased CO2, roots become more numerous, longer, thicker and faster growing in many plant species. When cloning plants, root growth appears 3-5 days sooner with CO2 enrichment versus without. Although some things are known about root response to enrichment, much remains to be learned. Nevertheless, it is clear that plant roots, like other parts of the plant, typically do better in enriched air versus ambient air.



What does light have to do with CO2?

Photosynthesis has two parts: the light-dependent reactions and the light-independent ones. The light-dependent part is the use of light to steal electrons from water. This process produces oxygen. The light-independent part is carbon fixation. Plants produce CO2 during respiration when they break down sugars, just as humans do. They do this day and night, but during photosynthesis they tend to take more out of the air than they put in. They reduce CO2 output during the carbon fixation steps of the light-independent reactions of photosynthesis. Both processes go on all of time, except carbon fixation tends to be more active during the day. Plants only release oxygen during the day since they require light to do it.



Does CO2 improve yields, or just make for healthier plants?

The answer is both. The goal of CO2 enrichment is to reduce the time from seedling to harvest and to speed up growth and increase yields. Plants grown with elevated CO2 levels are better able to resist insects and diseases, which makes for healthier plants. In a recent study, lettuce grown in a greenhouse with ambient air was compared with lettuce grown in a greenhouse with enrichment. The test showed the lettuce grown in the greenhouse with ambient air was ready to harvest in 59 days. In the greenhouse with CO2 enrichment, the lettuce was harvested in 48 days. By weight, the CO2-enriched greenhouse lettuce weighed 30% more. In studies at our farm, we have found supplying tomato plants with elevated CO2 produces 20% more tomatoes than plants that do not receive the elevated levels. By harvestable weight, the plants receiving more CO2 out-produced those without by 25%. In another test, strawberries grown with elevated levels of CO2 contained more sugars and physical mass to support a greater number of flowering sites.



Can you ever have too much CO2?

Too much CO2 can be detrimental for plants. When levels get too high, the plant’s ability to perform transpiration during photosynthesis is reduced. With lower transpiration rates, fewer nutrients are drawn through the plant, so less food enters the plant and growth slows down. High levels can cause necrosis spots to appear on leaves. These dead tissue spots are an invitation for bacteria and mold to appear and cause even more plant damage. CO2 levels in the 1,200-1,500-ppm range are ideal, depending on what you’re growing. With levels above this, you are only wasting CO2 and potentially asking for trouble.



When beginning CO2 enrichment in a garden, the first thing you will notice is a greener garden. This is proof your garden is benefiting from the CO2 you are providing. Greener plants mean more chlorophyll is present in the leaves and more photosynthesis is taking place. There are many ways to set up CO2 enrichment. Do some research to find the best option for you.

Then after that maybe you should read this chapter i have laid out here for you as well since u clearly have no understanding of nutrients or their uptake and roll in a plants life go back to school and quit trolling little boy

http://www.myhydrolife.com/the-missing-ingredient-co2/ you may have to cut and paste this or even Google it as I typed it in but there it is black and white and something tells me he know's a hell of a lot more than someone like you who just likes to make claims and feel smart about it have a great day hope u learn something but I doubt it as it is clearly to advanced for you

He has absolutely no study or proof on his 2200-1500 ppm claims . it was one sentence out of 8 paragraphs

You have none dude he has been the top botany reasrcher in the world for over 40 years. that was a brief overview by someone else who also takes his courses for advanced botany of commercial agriculture and economical, eviromental advance and was aked to dumb it down a bit because he was using quotes from Howards books that most could not understand thefore was asked to make it legable for the basic grower to understand and therefore it was published on that site for everyone. And the more you try bs the subject the less reputable you become as a valid grower or reputable source for information if you even have one I am sorry you don't like the facts or just like to try and make yourself feel like you know anything on this level of cultivation but you are wrong you have been proven wrong I can site at least a dozen more books from different authors and probably thousands of threads where the same information can be found on other grow sites and I will no longer be little myself by talking to you have a great day

I don't use CO2 anymore and to be honest, I am seeing better results than when I did.

There is no set spot though. So many things to factor in. VPD, genetics, what you are feeding them.

I see that this thread is in Organic Soil.....and while I may be wrong, I have always heard that using co2 in organic soil is not really worth it as you can't push your plants as hard as you can in a hydro medium.

I agree to an extent @CelticEBE But I Don't Feel It's Worthless In Soil Just Much More Complicated To Control Because You Do Not Have Full Control Of Nutes In The Plant Without Flushing very well Every two weeks but with that knowledge and a very good understanding of what you plant Wants/needs it will work almost if not just as good as hydro

Props on great information and getting this thing back on the road

Geeeez,everyone chill......smoke a j thanks for all the super detailed info, no need for pissing match! !! I don't believe in hydro,only all natural recycled true living organics,works for me tastes great,and the co2 seems to definitely doing what it's supposed to be

Mr.sativa said:

Can't with my work schedule,definitely will take that in consideration after this run almost done bout a month left. So will my ac suck out the co2 or just recirculation it,I have a 14000 btu a/c on wheels the window vented type,it's set on 80° now

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If the room isnt sealed its not very efficient use of co2, still might be worth it. And 2 1000 watt lights in a 12x12 might be a little less than optimal. If you add more lights you add more heat and the ac runs more and you lose more co2. How tall is the ceiling? What is the humidity? If you have 10' ceilings it would help with the heat. Put a portable swamp cooler in there. If you are not around all day to crack the door when it gets too hot then set the ac to come on around 90'. In a sealed room I would like to run 75', 65%, in your case I would go hot and humid. The higher the temps the higher humidity has to be. I have done something like that humidity always up around 80%, 12x12 room, 2 1000 watt hps, but I was there to open the door when it got too hot. no issues with bud rot, but it was always a concern. I was going through about 4 20 pound co2 tanks a month, I think. I remember a smaller room, tightly sealed, lights on at night during the winter, a 50 pound tank lasted the entire bloom, two months. I had a controller on that tank though, on at 900 ppm and off 1400 ppm.

kuz said:

If the room isnt sealed its not very efficient use of co2, still might be worth it. And 2 1000 watt lights in a 12x12 might be a little less than optimal. If you add more lights you add more heat and the ac runs more and you lose more co2. How tall is the ceiling? What is the humidity? If you have 10' ceilings it would help with the heat. Put a portable swamp cooler in there. If you are not around all day to crack the door when it gets too hot then set the ac to come on around 90'. In a sealed room I would like to run 75', 65%, in your case I would go hot and humid. The higher the temps the higher humidity has to be. I have done something like that humidity always up around 80%, 12x12 room, 2 1000 watt hps, but I was there to open the door when it got too hot. no issues with bud rot, but it was always a concern. I was going through about 4 20 pound co2 tanks a month, I think. I remember a smaller room, tightly sealed, lights on at night during the winter, a 50 pound tank lasted the entire bloom, two months. I had a controller on that tank though, on at 900 ppm and off 1400 ppm.

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Right now Temps staying @ 80° rh 65 during day,all day everything on individual thermostat ac, dehu, it has 8' ceilings and night Temps drop about 4-5°, rh stays about same hoods are air cooled from under house

Tank lasts 3 weeks @ 1000ppm,room is definitely sealed tight,doors and windows,floor etc. Only got 7 plants on 2k gets extremely hot with no ac,like over 90°,

Mr.sativa said:

Right now Temps staying @ 80° rh 65 during day,all day everything on individual thermostat ac, dehu, it has 8' ceilings and night Temps drop about 4-5°, rh stays about same hoods are air cooled from under house

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If you look at a vpd chart you want to be a little cooler or a little more humid. Though IME you are right in the sweet spot. Have you ran co2 before? The bud looks great, I would say your pretty well dialed in.
I dont know much about ac, but if its not a heat pump I think you are leaking air somewhere. Personally I think its still worth it. I recently saw a co2 monitor on amazon for $113, if you wanted to know for sure.

I have heard you need higher temps for co2 to be effective, I think its another myth.

I havent seen it in person, but heard of people pulling 2 pounds a light with living organics, so I think it can be worth it to add co2.

2lb a light! Do you know if hydro soil ?what size pot? how many plants? RH temp? co2 ppm? maybe a link? That's outrageous!

Mr.sativa said:

View attachment 516700 Geeeez,everyone chill......smoke a j thanks for all the super detailed info, no need for pissing match! !! I don't believe in hydro,only all natural recycled true living organics,works for me tastes great,and the co2 seems to definitely doing what it's supposed to be

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Dont believe in hydro :sorry: permaculture organic enough for you these guys offer organics and their recommendations are to only use organics and teas in this system which is mentioned in a separate video I am absolutely dieing to build a 9 spot system

KiLoEleMeNt said:

2lb a light! Do you know if hydro soil ?what size pot? how many plants? RH temp? co2 ppm? maybe a link? That's outrageous!

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I dont really know the details. I have a hard time believing it also, but I am switching over. Biggest thing for me is reusing the soil.

kuz said:

I have heard you need higher temps for co2 to be effective, I think its another myth.

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me too......iv never understood why its recommended higher temps for co2...... wouldn't you want higher humidity so the stomata is fully open to better absorb the co2? I think co2 in veg is more beneficial than in flower. I too don't agree with a lot of what @KiLoEleMeNt posted...... not that it isn't useful and informative, but temps over 80? humidity under 60? co2 12-1500, high ec, no mention anywhere of vpd.... I ran those parameters for a few years when I first started growing, and I grew shitty weed.