Heat problem solved with co2?

42 Days into first grow. 2x4 tent, 4 inch vivosun fan and filter, 2 oscillating fans, 2 x 300 watt vivosun LED’s, coco, cloth pots 3 gal, SOG, foxfarm trio plus cal mag. Gorillia Glue, auto, fem. Flowering. Running hot, 85 to 87 degrees at time. Humidity 47 to 52%. Will a sugar / yeast CO2 generator help?

85-87 is pretty high, but CO2 isn’t going to help with your situation. You do need to push higher temps with CO2, but with your lighting the plant won’t be able to use the extra CO2.

I would suggest increasing airflow around the plant.


Nope. Those won’t even be fully producing before harvest. Then it’s uncontrolled. And with your exhaust you are pushing heights. So a sealed environment would mean even more heat. Are you running 600w actual? Using those two lights in a 2x4 is a good idea as you wouldn’t have to run them at 100%… making them last longer in turn. Since I’m sure you are overshooting dli.
600w in a 2x4 should definitely be enough light to utilize some CO2. Since I feel that if you actually did dli measurements you’d find that you are at a higher than usable dli without CO2. That’s more than double I use in same area .


I have tried everything to reduce heat. Maybe a winter grow makes more sense. It is easy to add heat and humidity. Difficult to take away. I have a 3rd fan going in today. It will be breezy in the tent. Air flow is high. Plants look ok, at least to my beginners eye.

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I wouldn’t worry too much about temps in the mid-80’s, but you definitely don’t want to let it get any higher.

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My main growing time is Nov to May due to South Texas heat and humidity.

If you can cool the room down, the tent temps will come down generally.

If I didn’t have a window ac the temps will hit near 100 degrees. I don’t have to worry about smell which makes it nice.

Should have went with a 6" exhaust fan, moves more air out of the tent, keeping temps lower. When you put a carbon filter on a 4" exhaust fan, it really kills the CFM. Putting in another circulation fan will not help with temps.

The Chinese light companies love to lie about watts, if this is the light you have then not really 300 watts, more like 120 watts.



Thinking same thing. :+1:


Not used to that one. Usually when they say a number not in the 1000s it’s close to actual wattage. If those are your lights then both of them together would do your area. But not enough light for CO2. Guess I should’ve checked. Lol. It also isn’t a full spectrum.

Full spectrum is this…

Starting to think black dog and HLG are the only companies that use numbers in the names that make sense. Lol. Since their numbers are what their actual wattage is. Like the phytomax 2 1000. Uses ~1050 actual watts. HLG 260, mine anyway, has a usable range 220w-280w. I could turn it up higher. But would shorten the life of the diodes.

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Yeah I think they’re catching on that people aren’t falling for the big fake numbers anymore so they’re toning it down LOL, but still trying to trick people.


Wow, I should have read the specs. Got to love it. So, I just learned I have 2 x 120W LED. Is this OK for a 2X4 tent? I am switching to a 6 inch vivosun fan today. I originally started with the 6 inch and it felt like a wind tunnel in my tent. Will try again an see impact on temp. Thanks

Not ideal, a bit under-powered but I’m sure it’ll grow you bud.