How to control temp in grow tent?

I have a 2x3x5 grow tent with an 100 cfm intake fan and an 4" carbon filter with 190 cfm fan and I’m running a 400 watt Mh (temps are getting up to 100 help please

Are you pulling air out from the top? What’s the temps coming into the tent? For now I’d open the tent up and shut down the light unless you’re in bloom.

How old are ur plants?

Have no plants in there at the moment want to get my temps down to a consistent 75 before I pop them. I keep the house on 74 when I’m home and 80 when I leave. No I have my carbon filter on the ground going to put it up there today.

That’s a pretty high wattage for your space ~67w/sq. foot. I’m not surprised it’s cranking hot in there. I agree with @bob31 asking if you’re exhausting from the top and pulling in from the bottom? Not sure I’d shut the lights off, though, unless you have cfls or something around. I wouldn’t put them into darkness :slight_smile:

Well that’s good. Had me worried there for a second.

Add extra fans 2 12" fans (oscillating) or a 20" oscillating fan adding the extra fans will help

1 Like

Very smart! :+1:

Wow. A couple blows on the bugle and the cavalry arrives. I love ilgm!


Lol noticed it as soon as it came up was busy replying else where lol

Also, are you using passive vents as well for intake? You’re pushing out twice as much as you’re pulling in. Some neg. pressure is good to control odor but the more airflow the better, assuming you’re not blasting air right on the plants.

If he adds an extra fan or two he can run it the same way and still cool it down

1 Like

I agree. Just trying to understand the entire picture. Sorry, my work training makes me want to dig…

Also another thing that can help is by going from a 4" carbon filter, to a 6" carbon filter to push more air, out @Swan1234

1 Like

my carbon filter is sitting on the ground in the corner of my tent. What would y’all suggest i do about my light size I really don’t have the money for a new light. What do y’all suggest I do?

Read above post and get that filter off the ground that may be your problem

1 Like

Move it to the top, that’s where the heat is. And do whatever @Majiktoker suggests, he’s the man!


And like @Majiktoker said, I have 2 fans in my tent. A big one blowing over the tops and a smaller one that my intake fan is blowing into so it’s immediately dispersing that fresh air around the tent.


The only problem is I have space issues with having that much stuff in the grow tent. When I get him I’ll post pics of the setup so I Can give y’all a better picture of what I’m working with


All the more reason to hang it up and out of the way. You can also hang your fan. I took the base off of mine drilled a hole, attached a chain, and hang that too. And it still oscillates. Floor space is nice to have :slight_smile:

1 Like

Cool, I can guide you a little better with picture lol