I have a grow box that 3.5'Lx2'Wx5'H. I just hung the lights and I'm thinking its a little too much. I have a Compact Fluorescent 125W Day Grow Light System w/ Dew Guard with a Full daylight 6400K spectrum incandescent grow bulb and a Full Spectrum Light Bulb - ALZO 85 watt CFL 5500K - daylight balanced pure white light - 4250 Lumens in a reflector I got from H.D. I wondering if its too much because I turned them both on and without the fans on it was like 90 degrees in there! Now I guess I'll have to scrap the cpu fans and get one of those 4" inline fans. I have 4 total, 2 for intake and 2 for exhaust. I cant seem to insert the pic but its in the gallery under my name. Is this too much?
Is this over kill
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PrairiePoet
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So you have two other bulbs besides the CFL? Only problem I see with that is heat, but you already know that.
I run 6 CFL's at 85 watt each in my closet, about the same size as yours. You have the right ideal, add more exhaust to it, and the temps will come down.
Prairie
I run 6 CFL's at 85 watt each in my closet, about the same size as yours. You have the right ideal, add more exhaust to it, and the temps will come down.
Prairie
That's only 30 watts per square foot of fluorescent lighting. It's not too much - it's not enough. Well, depending on whether you've got the lights (and plants) concentrated over a small portion of the space and such.
Anything that adds heat - and that includes CFLs - in a confined space is going to add heat. Your box is 35 cubic feet. How much air are your fans actually moving?
Anything that adds heat - and that includes CFLs - in a confined space is going to add heat. Your box is 35 cubic feet. How much air are your fans actually moving?
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I have total of 4 cpu fans that run 1200rpm at 44.73 cfm apiece. Two up top Exhaust and two on the bottom intake. I just got my fan controller in for the exhaust. Still waiting for the one for the intake. Got the temps down to 80 degrees with just the exhaust running. That was the reading on the top part of the cab. I 'll take one on the bottom as someone got me straight that the temps might and should be lower on the bottom of the cab where the plants will actually sit in the beginning. I think I can get them down below 75 with the intake fans on. We'll see. How much more light should I add?
PrairiePoet
Well-Known Member
The problem with coming out and saying, "Oh add two more bulbs..." is the other side of it. How much heat is going to be generated, and can you handle it.
My first grow I started with two 85 watt bulbs. Next grow I added one more. And I started to have heat problems. Figure that out, more CFM exhaust and better ducting light fixture. Then on the fifth grow I added three more bulbs. I'm in the end of the sixth, and I'm rethinking the lights again. I can handle the heat like this, except on the hottest days (but more of a humidity problem that comes with the outside air). I'll either add three more, or scrap the whole things and go with smaller wattage, but many more bulbs.
So the best answer I can think of, is to just keep adding bulbs slowly. All the while keeping an eye on the temps. Temps should be different when the plants are young compared to flowering.
Hope that helps.
Prairie
My first grow I started with two 85 watt bulbs. Next grow I added one more. And I started to have heat problems. Figure that out, more CFM exhaust and better ducting light fixture. Then on the fifth grow I added three more bulbs. I'm in the end of the sixth, and I'm rethinking the lights again. I can handle the heat like this, except on the hottest days (but more of a humidity problem that comes with the outside air). I'll either add three more, or scrap the whole things and go with smaller wattage, but many more bulbs.
So the best answer I can think of, is to just keep adding bulbs slowly. All the while keeping an eye on the temps. Temps should be different when the plants are young compared to flowering.
Hope that helps.
Prairie
Seems to me that you'd be much better off removing your intake fans from the intake vents and using them for more exhaust. (Enlarging your intake vents if needed.)
If you've got 88cfm exhaust and adequately-sized passive intakes, you'll get 88cfm of airflow. If you have 88cfm exhaust and 88cfm intake... You'll still only have 88cfm of airflow. Stick them all on exhaust-duty (again, assuming that you have properly-sized intake ports) and you'll have 176cfm of airflow.
So... You've got 510 watts' worth of 85-watt CFLs producing heat in your GR and in addition to the heat you've got a humidity issue due to the fact that you're venting the entire grow?
Have I correctly understood? If so... You know, with a good air-cooled 400-watt (or 430-watt) HID setup you'll most likely produce higher yields. You'll also be able to take care of any issues caused by venting because you can vent/cool a sealed fixture completely separately from your GR (bring air in, pass it through the fixture, and send it back out). You'll also be saving electricity due to running less light wattage.
Just something to think about.
PrairiePoet
Well-Known Member
I noticed that also, and fully agree with with TS. Exhaust out, keep a negative pressure in the GR.
Yes, you did.
Actually I have. I wished I had more space to work with, then HID would be the way I'd go.
I'm trying to get my flower room to have more than one grow in at a time. I'd like three, but I might only have working room for two. Right now my light setup only covers 2/3 of the screen level very well. Though I train and let the sides go higher to get closer to the light.
So I am wondering on the 400, I'll have to keep it farther away the older grow, would that be too far for a new grow? I was think with the CFL's I could have two light fixtures.
Thanks for the suggestion. I need to think and do some calculations.
Prairie
