I'm growing in a cabinet about 6 feet tall, 3 feet wide, and 2 feet deep with a 400WATT HPS and the temps just will not stay in the range of 70-80.

I have the top of it pretty much all cut out, with a 20inch window fan pushing air out and a 10inch oscillating fan practically touching the HPS. The entire bottom of the box is cut out to supply air also.

The weirdest part is that when I open the doors the temperature barely drops at all, and at night is when they're highest. The temperature has ranged from 75-90, what the hell should I do?

if you have the thermometer in the sunlight of the light it will give you a false higher reading I believe,

try putting in a shade part of the box. maybe someone else can elaborte if I am right?

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"They must find it difficult...Those who have taken authority as the truth, rather than the truth as authority"

Are you venting the heat out of the area? Most people use ducting to take the heat out of the growing area. By out of the area I mean so that the warm air cannot be sucked back in passively.

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One sec...I am trying to think of something clever...
Got CFL? http://www.rollitup.org/cfl-growing/71259-cfl-sog.html

That’s a small area for a 400w. You say you have the top off with a fan pulling hot air out and a fan blowing cool air in on the bottom and it still gets in the 90's? I had the same trouble with mine and I switched to a 250w hps and a couple CFL and it really helped. With this small of an area you would prob be good with just the 250w hps and nothing else as it will take care of 4-5 plants alone easy. good luck

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For 400 dollars I got Jerry Garcia in a pouch, man!

You could also try a cool tube or a vented reflector. That worked for me.

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One sec...I am trying to think of something clever...
Got CFL? http://www.rollitup.org/cfl-growing/71259-cfl-sog.html

Panda, that makes sense to me, anyone else experienced something like that?

Tanuvan, yes I'm venting the air out of the box.

Glockstar, its ridiculous that the temps are that high isn't it? Its so goddamn frustrating, forgive my language

If I can't get anything to work I guess I will have to get a 250Watter, anyone wanna trade theirs for a 400Watt plus a little cash haha? I probably should have just bought a cooltube.

Before some suggests this, the ballast is already outside of the cabinet.

My friend has enough trouble keeping his box of the same size at acceptable temps with at 250W HPS. Large case fan pulling air out of the lamp/reflector and it has cool glass. Still hitting 85 degrees if doors are sealed shut...

If it's only going up to 90, you don't have anything to worry about. It might not be the optimal temperature but it certainly won't hurt them. My grow cabinet stays about 90-92 and my plants are growing an inch a day and couldn't be healthier.

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http://www.rollitup.org/grow-journal...idow-grow.html

also man the temperature of your house is key, what are the temps of the room in there? i would keep what down too

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"They must find it difficult...Those who have taken authority as the truth, rather than the truth as authority"