Temps and CO2?

So I forget, temps can be higher, like around 85+ I recall when enriching with co2 but does it have to be at some level meaning will it still work at lower temps? If now that my temps are lower due to weather do I need to keep the night temps above what and the day can be how low and still not have a negative growth impack? I can keep the room at 72 with 1k hps and co2 if I choose or with no co2 for sure but will this slow them up much during lights on that is.. I pull air in for outside so it can be pretty cold. Have a heater but can keep it lower if no worries. Thanks....

I guess the real answer to this question will come from results of your grow. 85 starts to get near a line I personally dont like to get near. @ 84 is when my cooling kicks in. High 70's to low 80's is best. CO2 will always be a benefit. While there might not be an economic reason, CO2 will always be a benefit to your plants.

Ecofrog is not really correct. Co2 enrichment allows plants to achieve higher metabolic rates that would otherwise not be possible due to co2 limitations. You need higher temperatures to make this faster metabolic rate happen because it's an endothermic reaction and therefore requires heat. My ambient air temps hover around 85 and my canopy temps are a cunt hair under 90...like 87. (so maybe an Asian cunt hair is a better analogy.

The bigger question is... Why the hell are you pumping outside air into your room while your using co2? Do you own a co2 manufacturing facility or something? Daytime air 85, night time no less than 75...your golden.

The economical reasons behind co2 are increased yields from 30-40% if all other factors are dialed in. That difference translated into about $2,000 for me on my last, 8 plant grow.

You are probably going to want to try to seal your grow room or you will be having to use alot of CO2. The higher the temperature the more efective CO2 will be, until a certain point obviously. I've done a good amount of research on using CO2 and in my opinion 90 dergrees is about perfect. I would recommend a little under 90 degrees to be safe as LF said. Also no one has metioned this. Make sure you have your humidity under control. I have seen convincing evidence that higher humidity may lessen the effects of CO2. I wouldn't be worried about it at night as plants are more focused on resin production and not metabollic or physical growth. Some turn CO2 off at night.

YO Alex. Head over tO the urban Gardner wetsite and read the article on vapor pressure deficit. Pretty interesting. I keep humidity in the low 80's in veg. But for flower drop it as low as I can get it

As long as temps don't dip into the 60s CO2 will work. Once you get at a cool enough temp to hinder growth the CO2 in the room will have little effect since the plant's biological functions have slowed to a crawl.

70-85 degrees is a good working range for Co2.

Ronjohn7779 said:

As long as temps don't dip into the 60s CO2 will work. Once you get at a cool enough temp to hinder growth the CO2 in the room will have little effect since the plant's biological functions have slowed to a crawl.

70-85 degrees is a good working range for Co2.

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If your running that cool (70s) I wouldn't pump co2 higher than 700/800 as the plants can not utilize is. Like I said, it's an endothermic reaction. If you don't know what that means then google it

I agree with LF if your running in the 70's CO2 is almost unnecessary that's too cold. Keep it above 80 or you will definately want to keep CO2 ppms low nowhere near 1500. Ill go check that artucle out now and I agree with you again lol i keep my humidity pretty high for the first week or so after transplant (sog so no veg time) and after that drop it as low as i can get it. The less humidity in the air the more your plants can "work" (burn carbs and really just grow in general) and transpire water into the air (creating humidity). Less humidity means less intake of water by the plant out of the air and more intake of CO2 from the surrounding environment. I read a post recently talking about the bottleneck effect i guess you would call it. If you are using CO2: co2 should be the bottleneck variable between the lighting, humidity, temperature, and co2 ppm of your garden. This means that, for example: lets say you have 1000w hps, low humidity (30's), and high temp (85). This is good. CO2 will be the bottleneck variable, or the variable of the four that may or may not be at it's maximum or peak level; the last variable considered in the 4 variable equation. Bad, for example, would be low temperatures in the 70s with 1000w hps, low humidity, and high co2 concentration. Or high temperatures, 1000whps, high humidity, and high co2 ppm. CO2 needs the other three variables to be at high levels in order to be effective, while the other three do not need co2 to be effective. What im getting at is that you really want to have every other part of your garden maxed out and dialed in before usin co2 or it will not be very effective. Gana go read that article now peace.

legallyflying said:

If your running that cool (70s) I wouldn't pump co2 higher than 700/800 as the plants can not utilize is. Like I said, it's an endothermic reaction. If you don't know what that means then google it

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I obviously know what an endothermic reaction means...Which is why I said if the room cools to a point where the plants biological functions halt then Co2 has no effect....You seem to know the definition yet you can't understand my very simplistic definition. I don't know why I'd google shit. Maybe instead of googling shit you should take the time to read what you copy and pasted off of google and understand it before you get on your high horse.

Also I gave him a working range from 70-85...Even you seem to think thats correct. I didn't specify the amount he should be generating, but the temps CO2 should work at. I wouldn't go over 85 degrees for various reason...germs, pests, humidity (loves high temps), ect.

Just stay around 80 and call it even lol seriously tho, keep it over 80 or co2 will be much less effective. It's just dumb to get your co2 all set up and be so close to a big jump in yield and then not have high enough temperatures. Keep em high. Like us!!!!!!!! I mean i can see their arguements, sure low temps will work if the plants ever need excess co2 they'll have it, but high temps with co2 makes a much larger gain in yield and i would just never have my temps below 80 if running co2.

my room temps are at 70. if i dont blow a large fan from the front (where the first pic is taken from) the top of the canopy will get to 88-91. if i do use a large fan blowing from the front (where pic1 is taken from) temps have a hard time getting over 80. i either remove the front facing side of insulation and blow a fan on them and have temps around 80 or i leave the insulation up and only blow a small fan in from the bottom of the one side.(where the middle pic is taken from) what do ya think? and im runnin 1500ppm co2

Ok well here is the deal. I have passive vents and a big carbon filter with fan. I open the vents at night only. The rest of the time the room is pretty tight. The other thing that bugs me is my 55 gallon rez gets to warm. It is covered and it is full but it still gets warm. I see many grows on here that have smaller rez's and no mention of chillers so my question is how to keep it cool if no chiller. My temps without co2 are around 78 with the one 1k hps. With the heater on and the vents closed and the co2 on the temps are staying at 83 to 87. So the rez gets even warmer with the extra heat. I have used smaller rez's in the past and they got warm also but I never have had a bad outcome due to the water temps even though I know it can be very bad. Have 3 big air stones in it too. Use a little h2o2 every so often as well but not much or often.. So anyway.. I am growing a strain that gets really big and busy and has way to many branches so I am trying lollipoping this test grow to see if I can get a single type cola grow thing done. I get great yields with all the side stuff in the past but it is such a pain in the asssholes. Thanks.

Alex Kelly said:

You are probably going to want to try to seal your grow room or you will be having to use alot of CO2. The higher the temperature the more efective CO2 will be, until a certain point obviously. I've done a good amount of research on using CO2 and in my opinion 90 dergrees is about perfect. I would recommend a little under 90 degrees to be safe as LF said. Also no one has metioned this. Make sure you have your humidity under control. I have seen convincing evidence that higher humidity may lessen the effects of CO2. I wouldn't be worried about it at night as plants are more focused on resin production and not metabollic or physical growth. Some turn CO2 off at night.

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my room temp when the light is off is 60 and the temp when the light is on 72room, 80-90canopy. so for now i get away without a chiller. rezs stay at 63-66.
this is the winter of course in the summer i still managed to keep the rezs under 70. make sure your air pumps are not in the light (they'll pump warmer air). and my floor stays cold so that helps my rez stay cooler too. also air blowing on a rez will make it heat up or cool off quicker. try not blowing warm air on the rez instead mayb blow air on the rez when the light is off if the air is cooler than your rez that is

Ronjohn7779 said:

I obviously know what an endothermic reaction means...Which is why I said if the room cools to a point where the plants biological functions halt then Co2 has no effect....You seem to know the definition yet you can't understand my very simplistic definition. I don't know why I'd google shit. Maybe instead of googling shit you should take the time to read what you copy and pasted off of google and understand it before you get on your high horse.

Also I gave him a working range from 70-85...Even you seem to think thats correct. I didn't specify the amount he should be generating, but the temps CO2 should work at. I wouldn't go over 85 degrees for various reason...germs, pests, humidity (loves high temps), ect.

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If you have no idea wtf you are talking about you should just stfu. Seriously. Stop giving bad advice about shit you don't truly understand. Legalyflying is completely correct. You need to run higher temps when you ENRICH c02. 70-85 is fine for a garden that is using ambient air. When you start enriching the air and running very high levels of c02 the temps need to be higher and the amount of light needs to be greater otherwise you are completely wasting the C02. This is a thread about enrichment. Not what temps plants can still make use of c02 at. Yes obviously they can still use C02 at 70 degrees. But that is far from optimal in a 1500 ppm environment. As far as pests and humidity go, if you are running c02 you should be running a sealed room. Therefore you will have a dehumidifier/Ac for controlling temps and humidity. Pests should be locked out since the room is sealed. And if you do manage to get bugs they can be killed by running the C02 at very high levels for a short amount of time.

Greensea, what sized dehu are you running? Your night time temps are pretty low. Ideally you should keep them above 70. Based upon my ability to google things and no actual knowledge or experience, lower night time temps will induce more stretch and it also slows down important nightime processes, specifically respiration and the utilization of carbohydrates fixed during photosynthesis.

I'm running a 50 pint dehu and it keeps nighttime temps around 75. I also exchange air from my external veg tent so that also keeps temps up. You definitely want to have a strong fan on the canopy, even more so when running co2 as the level of co2 at the leaf surface (boundary layer) will decrease through plant uptake and you want to replenish that co2. BTW, you don't need 1500 ppm until the 3rd or so week of flower. I also drop down to 700-800 the last two weeks. With plants that small you will likely reap the same benefits with 1100-1200. Everyone always parrots out the 1500 ppm level (even those that don't even have co2) but my research has uncovered that the most cost effective (and highest quality bud) approach uses a range of co2.

To the other dude with high Rez temps, is there anyway to keep your Rez outside the room? This is ideal and my Rex stays around 65 sitting in a concrete floor. Another thing to consider is covering your grow medium to keep the hydroton cooler so less heat is transferred to the nute solution. Check out my scrog thread in my sig to see how I used panda film to cover the table. I switched to bucket ebb/flow and I'm using squares of that bubble foil radiant heat barrier stuff from HD.

Alex, I keep my humidity high until the buds start getting big and I'm worried about mold. I know it seems intuitive that plants will transpire more in high heat, low humidity bur there are limits to this and even with moist roots, the stomata will close to constrict to conserve moisture. At least that is what I have read and I know many plants employ this mechanism. I don't know specifically about mj however, maybe it does not constrict it's stomata as much as it has other mechanisms to prevent desiccation (trichomes)? At any rate, when I am forced to keep humidity low (40's), then I drop my temps to around 83-85.

Hey ronjon, relative humidity actually DECREASES with increased temps. Temps above 85 dont create additional pest problems outside of a slight increase in maturation rates in some pest species like fungus knats. I know you already know this and shouldn't google it but do it anyways, discussions usually go a little better when they are sprinkled with actual facts.

Banditt said:

If you have no idea wtf you are talking about you should just stfu. Seriously. Stop giving bad advice about shit you don't truly understand. Legalyflying is completely correct. You need to run higher temps when you ENRICH c02. 70-85 is fine for a garden that is using ambient air. When you start enriching the air and running very high levels of c02 the temps need to be higher and the amount of light needs to be greater otherwise you are completely wasting the C02. This is a thread about enrichment. Not what temps plants can still make use of c02 at. Yes obviously they can still use C02 at 70 degrees. But that is far from optimal in a 1500 ppm environment. As far as pests and humidity go, if you are running c02 you should be running a sealed room. Therefore you will have a dehumidifier/Ac for controlling temps and humidity. Pests should be locked out since the room is sealed. And if you do manage to get bugs they can be killed by running the C02 at very high levels for a short amount of time.

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Agreed. Nuff said.

i got alittle more strech than i wanted but not to bad, just a couple more inches than i wanted. i think im going to add a heater durning the dark period untill the weather warms up some. the room has no heat so when the lights are off it gets to cold. i havent been running a dehu because, its been staying around 35-40% with the lights on and about 40-45 when there off. i just hate the idea of heating the room with electric but, i guess im going to for the next month or two. i think next round i wont run the co2 for the first couple weeks of flower and try to keep them even shorter. talking about strech because of cold night temp, i remember reading about increasing the temp for the first hour or two after the lights go off to practically stop all stretching. anyone know anything about this?

Great info guys this is good stuff and you should really take the advice ronjon. They're right about the temps. It's still ok to use co2 with temps below 80 but as they said it will not be nearly as effective. LF i run sog so i like to transplant my clones and give em bout a week with some humidity to get settled in and then comes high levels of co2 and humidity as low as i can get it. I think were on a similar page with how we "enrich" wuth co2. I also like the point one of you brought up about the 1500ppm mark. That really is an overused standard for co2 levels. All rooms will be different i guess the only way to find the peak ppm of co2 enrichment for your room/current strain (without giving too much co2 and wasting money and precious gas) is to run a few harvests and up the levels until you don't see any additional growth. Informative thread tho.

I read something in maximum yield about PPM ranges for Co2 and they said very low PPM during the last two weeks. Did some searching on various forums and there are definitely some that have much more experience than I that found a decrease in potency with high co2 at the end of the cycle. For the life of me I can't figure out way (physiologically). I would LOVE to get down to 35-40% humidity but fuck an ehh, I was running a 50 pint, a 25 pint, and my aircon in weeks 5-8 and STILL couldn't get below 50% for more than a few hours. I bought a higher quality hydrometer though so maybe my cheap one and the ones on the dehumidifiers were wrong.

Time will tell.

Greensea, never heard of that. I built a new veg tent and it got pretty cold at night, they plants stretched like a mother fucker Changed ventilation around to combat this but haven't run a veg cycle with the new set-up. Should know in a couple of weeks . A do know that my plants just sprouted pistils