Proper temps for CO2? 70's or 80's? Why?

[Citizen024]

Who wants to share their opinion on CO2 room temps? Many say you need to run 80-85 as the ideal to help accelerate the growth. Others say no, still the mid 70's range per normal, and that 80's are acceptible but not optimum. They further say the reason 80's has become the standard is simply because it is very tricky (or expensive AC) to keep a CO2 room cooled that low, as most sealed rooms tend to be warm.

I am at 70 degree'ish without my dehumi- rh ambient is like 70%'ish+, so I have to bring it down. Lights are air cooled very well. I have a sealed well insulated room, at least that is the hope once I turn on CO2. With the dehumi on, and some vent running I sit right now at 78 degrees- 60% humidity. When I turn the vent fan off it will get warmer and a dryer something like 80 degrees-55/58% humidity.

I have a AC I can kick on- but that will dump heat into my veg area, and ultimately will get pulled into my flowering cooling light loop on its journey out. It is possible for me to overwhelm the system if I turn on an AC during the hotter months. In addition its noisy and pricey.

So in the end- it is better to run CO2 in the 70's, 80 or up to 85?

I have seen first hand several 80-85 gardens, but can't say I have seen a 70's w/CO2.

 

[grow1620]

I've read that the optimal temp for MJ's metabolism is around 85...but the only way to utilize that metabolism is to meet all the other needs of the plant, like c02, nutes, light...etc If you ran temps at 85 with no co2 the plant isn't recieving enough co2 to metabolize the nutes and light it's getting therefore it overheats because it can't process energy to it's full potential. if you were to run co2 at 75degees instead the plant can't properly utilize everything available to it, including co2 because the temp would be the weakest link.

but don't listen to me, I've never even run co2 just going by memory from what I've read. I would cite exactly where I read that but it's buried somewhere in a 770+ paged thread on rui, stinkbud's thread if you're interested.

 

[sparkjumper]

The people that say normal temps are optimum when using co2 enrichment have never used it successfully,I can guarantee you.85 degrees F at the canopy is what you are shooting for at 1500PPM and its worth it to use a IR lazer thermometer.Anyway the most important thing when using co2 besides being within the obvious parameters is using a controller.Not a cyclestat timer or a formula but a co2 controller!I cant emphasize how important it is to have control of that gas to avoid fluctuations.Using a real controller and having the balls to grow flowering plants in 85 degree F was the best move I ever did.Hell when they are stretching the first 2-3 weeks hit them hard with nitrogen and 90 F can be better for some strains.A lazer thermometer is a big plus I use the fluke 62 mini to check canopy temps,humidity dome temps etc.You must have complete temp and humidity control and at least 50 watts a sq ft.I run 3 1K vertizontals in an 8 by 8 cube with a 12K BTU window AC and a dehumidifier

 

[Lazyman]

Good advice from the guys above, the stomata on plant leaves are wide open at 85, so they are respirating at maximum rate, and with CO2, they uptake more CO2, water, and nutes then they do at lower levels. Prepare for fast growth and extra watering! Oh, and bugs love warmer temps too, mites in particular love warm temps and will reproduce MUCH faster.

 

[max_well]

similar thread

similar thread

I've been pondering the same ideas...
here's a similar thread
https://www.icmag.com/ic/showthread.php?p=2574208

 

[ganja din]

Hey

Ideal temp with Co2 @700ppm is 82F. I have not found journal articles experimenting with higher levels of Co2. Millions of years ago when C3 plants (like cannabis) where first evolving, the atmospheric Co2 was ~700ppm. Hence most researchers think 700-1000ppm is target level. That's not to say 1500ppm isn't better, but I haven't seen a difference from 700ppm.

Anyway, 82F offers the highest level of photosynthesis, given enough photons (HID light) is available, and the Co2 is at or above 700 ppm.

I keep my temp at 80-85F. When first flowering, during pre-flower (ie the stretch) it's wise to keep day/night temps within 5 degrees. This limits the stretch of preflowering.

I don't' have the journal articles on hand, but I can reference them if anyone is interested.

HTH

 

[Citizen024]

Thank you all for the wealth of knowledge, it falls exactly into my experience and thinking. I do have trellis's and hydro systems, so I am prepared for the growth increase.

The real challenge in CO2 is the room design and environmental control neccessary. Closed rooms are FAR more a challenge then simply moving tons of air through them. Every thing is insulated: room, ducting, ceiling, doors, all of it. I can fan speed control the lights so if I need to I can let more heat in the room. Heat is not hard to make

It maintains a really even environment, as well as letting the heat flow around the room well without seeping in. My vent design is the best I have ever done.

I am stoked, because I will meet the "perfect" temp zone without having to turn on my AC (and having 3000w of light stay that cool in a sealed room with everything else is real trick)- and I can resort to it on the really hot days. That really has been my goal, and this was confirming that I am there.

I used CO2 before in a closet- way different and easier to control then a room.

I am going with a Sentinel monitor- with fuzzy logic. I hear they have a great warranty policy, and co2 monitors are notorious for breaking. Sentinel in general is a good company from my experience. Not into CAP. Any feedback on monitor selection?

 

[noone88]

You need to invest in a infrared laser thermometer. The temps of the canopy under the lights are higher than the room ambient.

For example, during my light cycle, my room temp is locked at 75-77F, which puts my canopy temps at 80 to 82F.

If you run your ambient temps at 80-85F, your canopy temps will be easily 90F.

Of course, this is all strain-specific. Certain strains can handle higher temps in an CO2-enriched environment with no ill-effects, while others will just exhibit signs of heat stress.

 

[Lazyman]

Sentinel should be fine, I assume you're using tanked CO2 and not a generator? Fuzzy logic modes only work on tanks, not gennies.

 

[odin_]

You need to invest in a infrared laser thermometer. The temps of the canopy under the lights are higher than the room ambient.

For example, during my light cycle, my room temp is locked at 75-77F, which puts my canopy temps at 80 to 82F.

If you run your ambient temps at 80-85F, your canopy temps will be easily 90F.

Of course, this is all strain-specific. Certain strains can handle higher temps in an CO2-enriched environment with no ill-effects, while others will just exhibit signs of heat stress.

this is good advice

 

[Citizen024]

Yep yep, no gene. That would force me to turn on an AC, and the noise and power drain are not good trade offs. Whatever I saved in getting propane instead of CO2 I would lose in combating the heat/humidity.

Besides- open flames are better avoided in all possible cases. I am all for gene's overall, especially in large spaces but not in this situation.

Lazyman- you and I are both on the Pura Vida coco thing right? I am really like the results. I have a thread in organic hydro forum on it.

 

[Lazyman]

Cool deal man, yeah I like the PV bloom, I think i like FN grow better though (much stronger.) I need to try some other things before I settle on anything though, looking forward to trying canna in one side and maybe lucas or FNB in the other.

I hear you on the generators, I like them in medium-to-large rooms, even with AC to keep it to 82-85. Especially nice for garage grows with a natural gas line already present, hooaah!

 

[sparkjumper]

A lazer thermometer is the bees knees.You know I have a 3-4 degree difference at the canopy depending on how hydrated the plants are?Thats badass