First Grow, First Post, Ventilation Advice Needed

Hello All, McNerdius here. This is my first post, as well as my first grow. I will soon put up a log of my grow, but until then i have an ODD issue. At least, it's odd to a n00ber like me. So here goes...

I planted my seeds (pre-germinated) on the 12th. They are doing well, although due to high-temperature issues i've had no choice but to have the lights about 4" up. My lighting is: one 26w 6500K and one 26w 2700K cfl. I am lighting a 6" by 1' area with 5 seedlings, all of which have sprouted. My grow-box is a trash can, white, about 3.25 feet tall. It is white. I have used my hole saw and put eight 3" holes in it along the top. (Top of the trash can... it gets flipped over on top of the seedlings so the holes are really on the bottom... see pics...) In addition, i have put holes in it for easy light adjustment. Nice ! Oh and i've had a fan in it from day one. 4" personal fan, doesn't do much but i figured it'd be plenty for 52 watts of light and 5 seedlings... right ? No.

With the lights 1.5" from the seedlings, the temp was around 85-90. Outside temp is 74. All the time. It's in a medium sized closet whose door is always open. No visible damage to plants on my n00bvision.

So, figuring 85-90 was too high, i upped the lights to about 3.5". That dropped it to 80 degrees. They began stretching, of course.

I said to myself... I want my lights low and my temps low too. I swapped in a bigass fan, lowered the lights a bit, and put in a third. Now the lights are 2*26w 6500K ... 1.5" above the plants, and a 26w 2700K about a foot up. The temp ? 85. I'm moving triple the air i was before, at least. I've checked the temp using an oldschool glass thermometer, and the thermocouple that came with my multimeter.

I KNOW i'm putting too much thought into this. i KNOW that if my plants are doing good then go with it if not back yo ass up and fix it. BUT WHY THE SHIT IS IT TEN FULL DEGREES HOTTER IN THERE !??!??! Am i crazy, or is 75 watts not a whole lot ? How do y'all keep it cool in ur stealth grows ? What r some temps u guys run ?

I just feel like i screwed up by putting this massive fan in there... losing a lot more light thru that hole and i'm not sure if the breeze is doing more harm than good. BAH.










PS They are on day 4 in the pics. Any help/advice is appreciated.

They look fine........ but the trash can is the cause of the problem..why not cut it and use the plastic as a hood and just hang above the seedlings.....you don't need to cover them especially if heat is a prob yes you loose a little light intensity.....but you can add more lights to the hood....use the fan that will make your seedlings strong....I keep my temps between 72-81....i run co2 so i can get away with higher temps...

jcdws602 said:

They look fine........ but the trash can is the cause of the problem..why not cut it and use the plastic as a hood and just hang above the seedlings.....you don't need to cover them especially if heat is a prob yes you loose a little light intensity.....but you can add more lights to the hood....use the fan that will make your seedlings strong....I keep my temps between 72-81....i run co2 so i can get away with higher temps...

Click to expand...

Yeah I would get rid of the trashcan. If you're really insistant on it, then try drawing the warm air OUT of it, rather than just blowing it around inside. Also - run your lights during the cooler time of day, leave 'em off for the hottest. Doing this brought my temps down by five degrees. Good luck!

DoeEyed - you know, it's the weirdest damn thing... With the 4 incher, i had tried both fan directions. Blowing air out actually *raised* the temps by a few degrees. I'll have to try it with the 9 incher.

This grow started as a pseudo-stealth. It was the same can, with 6 lights and the fan all on one side. turn it around, and voila, no visible oddities. Except the fact that it's the brightest thing in the room and loud to boot. So i ditched the stealth idea, and now the can is really just a frame. Given the advice i've been... given... I am going to put as many holes in the can as i physically can. It'll be just that... a frame to hold the lights and fan. I'll make some popcan reflectors for the CFLs (searching for a howto on that one) and see where i'm at.

Also... i have the fan on low. Would High be too windy ?

Thanks for the tips so far.

Heh... i'll see if this does anything good for me:



I'll be doing popcan reflectors too... probably tomorrow. i don't have any empty pop cans right now goshdarnit.