Advice on grow room temps and Co2

In my current setup I have to leave the door cracked to my closet to keep the temps from reaching the low to mid 90's. I've always heard that higher temps cause the plants to shut down, my question is if I have adequate co2 in the room will the plants continue to grow a flower if the temps reach the low to mid 90's? I'm sure I'm just wasting the co2 if the door isn't closed.

your gonna have to vent if your temps are getting that high.
I'm pretty sure the plants absorption rate goes down as the temp goes up.
How many ppm co2 do you have when the temp gets that high?

I had the same issue, fans are key to exhausting heat away from the plant, i guess it kinda depends on your set up tho, its a lot easier to control heat with a grow box than just in the closet. But also if you have the option try to get one of those window fans that you can reverse, so you can control the heat in the room a little better. I don't know much about CO2 so I can't help you there. Good luck!

Adding CO2 to a room you can't keep cool enough is a band aide fix.

Fix the temps, *then* add CO2.

topfuel29 said:

your gonna have to vent if your temps are getting that high.
I'm pretty sure the plants absorption rate goes down as the temp goes up.
How many ppm co2 do you have when the temp gets that high?

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Thanks top, I've got a squirrel cage exhausting the heat, i've got to leave the door cracked about a 1/2 inch to let the heat escape. I haven't applied the co2 because I thought it'd all go out the door crack.

BigBudBalls said:

Adding CO2 to a room you can't keep cool enough is a band aide fix.

Fix the temps, *then* add CO2.

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Thanks Balls, that's what I figured. I was hoping that adding the co2 would allow me to keep the door closed at all times but that dosen't seem to be the case.

kmo8762 said:

Thanks Balls, that's what I figured. I was hoping that adding the co2 would allow me to keep the door closed at all times but that dosen't seem to be the case.

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It will, but also consider that THC will start to degrade at higher temps (over 90F I think, not sure) So its a moot point if flowering ; no gain.

But also if temp are that high with venting fans on, CO2 will be wasted (and maybe not used) and sucked out of the room.
Now, temps high with vent fans off is a different story, you can juggle the schedule to makes things effective.

BigBudBalls said:

It will, but also consider that THC will start to degrade at higher temps (over 90F I think, not sure) So its a moot point if flowering ; no gain.

But also if temp are that high with venting fans on, CO2 will be wasted (and maybe not used) and sucked out of the room.
Now, temps high with vent fans off is a different story, you can juggle the schedule to makes things effective.

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That's why I love this site, you can find out what you need to know without a lot of bullshit. +rep to you Balls.

adding to this i have a question in the same realm... my closet grow after adding two 27 watt daylight cfl's jumped to 90 degrees after i closed it up... I have a nice fan in the room blowing across the bulbs and the plants... i want to add another 105 watt full spectrum but im worried the temps then would spike over 90... so now i have 2 26 watt soft white and 2 27 watt daylight.. is there any way to cool the room down without adding an exhaust <not using a mini AC>?

homegrwn said:

adding to this i have a question in the same realm... my closet grow after adding two 27 watt daylight cfl's jumped to 90 degrees after i closed it up... I have a nice fan in the room blowing across the bulbs and the plants... i want to add another 105 watt full spectrum but im worried the temps then would spike over 90... so now i have 2 26 watt soft white and 2 27 watt daylight.. is there any way to cool the room down without adding an exhaust <not using a mini AC>?

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Grow rooms, boxes, tents, etc all need 2 types of fans.

First fan is a circulation fan, like you have to move the air around, sway the plants a bit (to strengthen the stalks) This fan does *nothing* to cool the room (actually adds an insignificant amount of heat)

Second is the ventilation fan. Draws in new/fresh air and exhausts the old stale (and quite possibly hot) air out if the area.

So with just the circulation fan, all you are doing is moving the hot air around the room.

yep yep got all that but is there a way to do this with out adding an exhaust.... that is my real question. I cant go and cut a hole i the wall since it is a rental and i will end up leaving here in half a year?

homegrwn said:

yep yep got all that but is there a way to do this with out adding an exhaust.... that is my real question. I cant go and cut a hole i the wall since it is a rental and i will end up leaving here in half a year?

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AC? Leave the door open? Buy a door and hack it. Replace door when you move. You can get a door for like $30.

homegrwn said:

yep yep got all that but is there a way to do this with out adding an exhaust.... that is my real question. I cant go and cut a hole i the wall since it is a rental and i will end up leaving here in half a year?

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If you don't want to buy a door or drill any holes.
Maybe you could Mod the door with some heavy carbboard.
leave the door open a foot or so, and put in a exhaust fan.

you could cool the room with out any fans or AC
there are Peltier thermal electric coolers.
in a nut shell you run a current through them and one side
gets really cold and the other side gets hot.
you put a few of these together and you could cool something down
there are no moving parts they make no noise.

topfuel29 said:

you could cool the room with out any fans or AC
there are Peltier thermal electric coolers.
in a nut shell you run a current through them and one side
gets really cold and the other side gets hot.
you put a few of these together and you could cool something down
there are no moving parts they make no noise.

Click to expand...

Peilters really wouldn't be a viable solution. They create more heat then cold. Gotta dump that extra heat somewhere. Plus hed need a lot to cool a room. He's having trouble cooling a couple CFLs.

BigBudBalls said:

Peilters really wouldn't be a viable solution. They create more heat then cold. Gotta dump that extra heat somewhere. Plus hed need a lot to cool a room. He's having trouble cooling a couple CFLs.

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thanks guys maybe i can rig the door with a fan in the top corner just cut the dam door. The problem is the closet is in the living room so its open for intrussion IE family friends... so its hard to be stealthy!!

Ok.. thanks balls... I had a revalation this morning at work... kinda weird...I think i cant pop a hole in the ceiling and or two... i found thes its an open ceiling because the original ceiling is 14ft. cathedral but the closet was not with the existing house it was build after it was sold for more storage... I went out and bought get this; computer fans at home depot... high performace 28cfm fans for yep a 1.29 haha i bought three... i can when i move use the hole and throw up a fake lamp socket with cover!!!

Nice how shit starts coming together... but hey one more question...

how long will the plant live with it being 90 degrees and if its off and on like say i leave the door open to drop it to 80 how long will it live if it spikes for a couple hours????

Will it use more water im using a wick system...
picks in my album check em out

I recently read that the plants stop growing at 85F so I would worry about those 90 degree spikes stressin your plants out

If your not running co2 ideal temps should be 70-80°…if you're running co2 ideal temps are 80-90° but cab go up to 95° without hurting the plant.