Basement growbox has low temps

Discussion in 'Grow Room Design/Setup' started by trchd1, Feb 3, 2011.

  1. I have a growbox in the basement. It is 4 foot wide 2.8 inches deep and 6 foot tall ( around 79 cubic feet )I'm running a 400 watt MH and a sunleaves windtunnel with a 4 inch opening. I think the CFM on it is 220. When I run the two at the same time I am getting temps to around 70 - 72 degrees. But when I turn the light off it drops down to 60 - 65 degrees. I'm running a negative air system and my inlet hole is at the bottom and it is 4 inches in diameter. My thermometer is sitting on the bottom and my light is at the top because right now I'm trying to germinate and I have a 4 foot flouresent on top of my seedlings, which are at the bottom.

    I was thinking of reducing the size of my inlet hole so that it doesnt suck so much of the cool basement air in.

    I have already tried using a speedster but the terrible and loud humming it creates made me disconnect because for one thing it sounds like it will ruin my fan in no time PLUS I'm trying to be super stealthy

    Does anybody else have any suggestions PLEASE?? I don't want to lose my babies:( Please help me

  2. So what do you plug in to this unit?

    If you plug the fan into it that would help bring up the temp during the day cycle but during the night my temps are still in the low 60's

    I dont see how it would work with the light
  3. you plug your fan into that... it speeds up and slows the fan to adjust for temp... it really depends on the temp of the basement.....

    you can also try putting a space heater blowing toward your intake... but when the light is on... it would get really hot in there...

    i believe the cap unit will solve the problem... but its just best guess, only you know your grow

    is your fan off at night?.....
  4. #5 Itsmeagain, Feb 4, 2011
    Last edited by a moderator: Feb 4, 2011
    I found a new heat bulb at the pet store last visit. I say bulb for like of a better term. Its actually just a heating element that screws into a light socket. (Doesn't emit any light.)
    I'm dieing to try one. But the wife says i cant spend anymore right now. :(

    Oops maybe not good! (Ceramic / Infrared Red bulb.) I'm really fried right now but I'm guessing that these would kill the plants?
    Heres a link anyway.
  5. I've been playing around with my intake size by adjusting it with duck tape and I'm getting a nice 82 degrees in there.

    But at night dont I need to keep the fan running for fresh air ??

    I like the idea of something like running a heatrock in there at night

    What is the lowest and highest temp ranges for my growroom??
  6. ideal range when the light is on is 75.. not higher than 80

    light off no lower than 55... ideal range 65-70

    and yeah.. the fan has to be on for fresh air... i was just checking to make sure
  7. Thank you very much Tihspeed !!
    • Like Like x 1
  8. fan does not need to be on at night, photsynthesis happens during the day (light on), the plant will sleep when light is off, no need to cycle, there isnt enough molecular activity when the lights ore off to require the exchange of grow room atmosphere. It all happens in the day light, lol, Resin is produced during lights off and that is all! Good luck grower, seasoned, builder of grow rooms and grower 7 times over. :wave:
  9. Lights off is when the temps are falling, dont cycle, get a humidifier of just leave everything off at night. What is the humidity of the area, :)wave: contractor, i can help.
  10. there ya go... turn the fan off... problem solved
  11. WOW! Thats a new one on me. You know while I was building my growbox I carefully studied the grow room forums on GC and I dont think one person said anything about not needing fresh air supply at night mode. Everybody was more concerned about getting the right CFM to cubic foot ratios

    I have everything BUT a humidity gauge. Where do I get one of these and what is the proper humidity during all of the growing phases?( from seedling to veg to flowering ) :confused:
    If the temperature ranges are what Tihspeed says they are then I am just about perfect with that due to my basement temperature which will always be around 60- 70 degrees naturally
  12. Seedling humidity- 75%
    vegetative- 60%
    flower- 40%
    clones in humidity dome-95%-100%:wave:
  13. You can get one of the cheap ones at Walmart.
    The reason that you see most people concerned about getting the correct cfm for the space is because that is naturally more important and some of us need help to figure it out, its not as easy as measuring nutes to water amounts ratios! What stage of the grow are you in?:wave:
  14. if you can maintain 60 deg. lights off, and 80- with lights on, you will be fine. Remember, its a weed, it will stand some stress, life for all living things is stressful.:wave:
  15. Thank you thefloweringman :wave:

    Right now my babies are just breaking soil and I have plastic bags over the cups to keep it moist and warm. So you say I can get a humidifier guage at W-mart?

    So whats the best way to create or reduce humidity levels in my growbox ??

    I plan on putting(6) 5 gal buckets in there so there wont be a whole lot of room but I can always mount to the walls inside
  16. yeah, the little ones read the temp and humidity at the same time. Creating humidity in the grow room is as simple as even putting a bowl or container of water open near the plants, let the light evaporate the water therefore creating the humidity you are after. Or when you are at Walmart, go to the pharmacy section, they have little desk top humidifiers that are cheap, they do well, it can last a full 8 hours before fast refill! dont over think it, put some water exposed, the humidity will rise. when your little ones get big enough, make sure not to just immediately take the humidity covers off for good, work them into the new environment slowly, take the bags off for a while then back on this way they wont be shocked when they get introduced to open air, they are tiny and they very impressionable. They wont be ready for another week or 2 anyway. (From the sound of things)
  17. Reducing the humidity requires the use of a dehumidifier of atmosphere cycling...
  18. Thanks
    I had taken two of the covers off of some plants that are showing some leaves. But I'll keep them on for a while and slowly adjust like you said along with a tray of water
  19. The reason why you don't see people turning the fan off at night is because of smell. You still need the fan and filter running unless you don't have enough plants to smell, or you don't care about the smell.

    Plus, it seems a lot better to have fresh air circulating even without lights on. Why have them sit in same air for half the day?

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