How many fans would I need for my grow tent?

Discussion in 'First Time Marijuana Growers' started by ZooeyLewis, Nov 18, 2011.

  1. Hey all!

    This is the tent that I'm waiting to get in the mail:
    It is the Growlab GL40. If the tent is 1'4 x 1'4 x 3'11 - how many fans do you think I would need? I can't seem to find information on how many fans, how many cfms or power or anything online. I'm not sure how to determine how many fans you would need for a certain space. Is there like an equation or rule of thumb? I'm completely clueless.

    My grow room isn't that big and I plan on growing 5 plants max (if they can even fit in there) and was thinking about using a couple of PC fans as a means for my air cooling in the tent.

    This one is less than $20 and comes in a pack of 4!
    [ame=]Coolermaster Cooler Master 120mm Silent Case Fan 4-in-1 Value Pack (R4-S2S-124K-GP): Electronics[/ame]

    I can also get a cheap PC fan air controller for about $20 as well and I would be able to control all the fans with this one controller.

    What do you guys think? And do you think I should get a fan controller for my *inline fan or a duct muffler to keep the noise down?


    * Inline Fan information:
    Exhaust Fans & Circulators > Suncourt 4" In-line Duct Fan - 80 cfm | Suncourt
  2. what type of lighting are you using??? and what are temps like outside of the tent?? and i dont believe 5 normal sized plants will fit in there....unless you grow them really small and LST/Top real crazy.....or maybe a SOG.....
  3. Hey Zooey,

    I JUST bought the exact same tent, and a 150w HPS light, to build a small, simple, inexpensive grow. If you have an HPS light, you'll need quite a bit of fan to deal with the heat. If you're using LED, you can get away with much less fan. What I'll be using for mine is the following:

    Main fan (to exhaust heat, and filter the smell)
    HTG Supply - GrowBright 4" High Velocity Inline Fan

    Thermostat for the main fan (to only kick on when it's too warm in the tent):
    DuctStat Plug Inline Voltage Thermostat

    Secondary fan (always on, just to draw in fresh CO2)
    HTG Supply - 4" Inline Duct Fan

    Both are drawing through a carbon filter:
    HTG Supply - GrowBright Pure Flow 4 Jr. Carbon Filter

    Mine might be a bit more advanced, but I have all the fans and thermostats already. At minimum, you'll need a 4" main fan, and a carbon filter:

    HTG Supply - A GrowBright 4" Inline Fan & Carbon Filter Combo

    Those PC fans you're looking at don't move enough air to do the job. Rather than a duct muffler, I'd get a fan speed controller, you can adjust the speed of the fan to drop the noise level if you'd like.

    That said, I'm modelling this little tent much after Dank's setup. Although it's a different brand tent, they're the same size. I think it would be worth your while to read his entire thread a couple times, until you understand how he's set up. Also check out his current grow in that tent. If you want more than one single plant in that tent, you'll need to grow a mother, take clones, and either lollipop them, or candlestick them, like he's doing in his. ( 6 tall, straight, single stalk plants, with NO side branching )

    That said, if you aren't prepared to grow mothers, I highly, highly, highly suggest you start out growing an autoflower strain in there, with a hempy bucket, using Lucas formula. Please google Hempy bucket, and Lucas formula, read as much as you can about them, then come back and ask questions, I'd be glad to answer anything I can.

    What kind of light are you using in there?
  4. Oh, By the way, yes, there is a "rule of thumb" for air circulation. Check the grow room design forum here, and there's a sticky. =)

    It's nice to hear someone asking for a reference so they can learn more about it, FYI. A lot of people are quick to just ask for an answer. The whole teach a man to fish thing... An inquisitive attitude will help you out tremendously in this activity!
  5. Thanks for the info! I'm going to be using a 125W CFL light
  6. Hi Zooey,

    OK, that's actually good news.. In that case, you may very well be able to use nothing but PC fans to control the heat in your tent. If smell isn't and issue for you, then you can get away with just that. If smell is an issue for you (assuming it is, like MOST of us), then you will need that more powerful fan to draw the air through the carbon filter, scrubbing the scent.

    Hopefully this info is useful to you. =)
  7. You sir, are the best!

    Although, I actually ended up upgrading my tent to the GL80. I realized that the GL40 wasn't nearly enough space for 5 plants so I went with that one.

    I'm gonna try using a 250W HPS lighting kit.What kind of hydroponic system do you recommend? I will be using coco coir and I think that may limit some of my options, but I was looking into Aeroponic systems. Can anyone confirm if Aeroponic (or Deep Water Culture) systems can be used in a grow tent successfully?
  8. 5 plants under a 250w is only 50w per plant...100 is the recomended
  9. #10 ZooeyLewis, Nov 28, 2011
    Last edited by a moderator: Nov 28, 2011
    [quote name='"TinTizzy"']5 plants under a 250w is only 50w per plant...100 is the recomended[/quote]

    Interesting. So you think I should get a 400W HPS System then?

    And would I be able to keep my clones in the same tent as my vegging plants under the same light?
  10. [quote name='"TinTizzy"']5 plants under a 250w is only 50w per plant...100 is the recomended[/quote]

    I'll be flowering 6 sativas in my DR40 under a 150w HPS. It'll start within two weeks. As long as you candle stick them, they're fine.
  11. Hey man, depending on your manicure and grow technique, you sure can fit those in the smaller tent. Yes, you can use aero ponies, or DWC inside your tent. See my DWC system, under my signature.

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