Temperature Question

Hey everyone. I have a 4x4x6.5 grow tent. I am using a 400w metal halide light. It is currently about 28 inches from the top of my plants. I am using a 140cfm (the room is 104cf) exhaust fan located at the top of the room and a small circulation fan just above the top of the plants. My temperature around the plants is 83F. I can't get it to go any lower than this and I know temperatures this high will slow growth if other conditions, such as CO2 ppm, aren't perfect. What should I do? If I can't get the temperatures any lower, then how much will the plants' growth be stunted? I don't have the money for a cooltube right now. I never thought a 400w would produce this much heat. I just spent a lot of money and it kinda makes me mad.

I am growing Super Silver Haze, White Rhino, Lemon Skunk, Hawaiian Snow, and Blue Venom if anyone was curious. They are about 3 inches tall right now. I am also waiting on some Dutch Delight.

you could spend a lttle more and get a cool tube for that 400. I had a 4x4x8 room. the cool tube dropped temp 10 deg. easy. Or get much cooler air going into your tent. also with the cool tube light is 4-6" off the plants.

My light fixture and reflector are older models and I am not even sure if I could modify it to fit a cooltube. I may have to just get a new light. I'm not sure though.

Actually, what is the cfm rating of the fan you are using with the cooltube Stumps?

I don't know. I had a 300 cfm squirle cage fan. Now it's a bathroom type fan but still a squrile cage. The cage is much smaller and the temps went up a little but not to bad. I used the light base of my 400 and put it in a diy tube. here's a pic don't have one of the fan set up.

I think I will just go ahead and buy a cooltube. I just don't know if I should use a 240 or 400 cfm fan. After getting the tube, I won't be able to afford one of the bigger fans.

the good blower fan is about 200 usd. Thats why I'm stuck with this one for awhile.

I think a 240cfm would work as long as it doesn't have far to go and no major bends in the duct. my fan is off the light about 6 ' and the out line is 10'

stumps said:

I think a 240cfm would work as long as it doesn't have far to go and no major bends in the duct. my fan is off the light about 6 ' and the out line is 10'

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Yea, I will probably go straight through the tent and connect the fan on the wall of the tent via a flange. I'm not really sure yet though. There are a few ways of going about it.