My Grow Box Is hovering around the mid 80's temp...can you help me? (see photo's)

Discussion in 'Closet / Cabinet Growing' started by Tol, Jan 14, 2013.

  1. Tol

    Tol Registered+

    Hi all! This is my first time growing and I've build a 2'length x 2' width x 4'height grow box and used a 400watt MH for vegging and currently using 400watt HPS for flowing. I'm on the second week of flowering 4 ladies, 3 Blue Dreams and 1 Bubba Kush. My temp has been always around the mid 80's. Will I be ok with this temp even if it is not the optimal temp? Can anyone suggest any additional modifications to my grow box please? Any help would be awesome. Thanks everyone in advance!

    Photo 1) Here's is a diagram of my grow box I drew up.
    Photo 2) My box at the earlier vegging stages.
    Photo 3) Showing a PC fan blowing on my HPS bulb to help with heat issues
    Photo 4) The lovely ladies before I trimmed them prior to vegging.

    photo 1.JPG
    photo 2.JPG
    photo 3.JPG
    • Dumb Dumb x 1
  2. low_rdr

    low_rdr Registered+

    You need less help than you think :)

    Move the fan from the light to the exhaust port, make sure there is nothing within 2' of your air intake on bottom, and nothing within 6-8" of your exhaust, your temps should move down, and moving your fan will also help your light distribution. Also, that looks like a very low quality mylar, or a very high quality foil - If its foil, remove it, and if you don't want to spend on the mylar, thats fine, just paint the inside a matte/flat white. All this should surely help with a mere 5 degree difference, if not, change the size of your exhaust hole :) I've got a 3x18"x3 with 600 watts worth of CFL's, and my temps are at a steady 75 during the day, 70 at night -

    I use a 4" powered intake 60 cfm's with a 8" powered exaust hooked to a carbon scrubber pulling 130 cfms - My intake is just above my lights, and my exaust is right at the plant level, the concept is the cool is is pulled over the lights, and through the plants, instead of forcing warm air out, I'm temping a cold air intake to remove excess heat from the lights- My lights are cool to the touch roughly 20 minutes after the box turns on, like, super cool to the touch, I often find my plants inside my lights, and there is hardly any burn issue, just adjust the plants, and I'm good to continue.
    • Like Like x 1
  3. Tol

    Tol Registered+

    How cool!!! My first reply and with awesome support! Thank you so much! I will have to make some further adjustments as you've stated and test it out.

    So are you saying that i need to move the fan from the light to the exhaust hole? Is this to boost the vaccuum or help with the airflow? You had mentioned not to block the exhaust within 6"-8" from the exhaust hole. Does this count for the fan as well? or should I put the fan right over the exhaust hole?
    Last edited: Jan 15, 2013
  4. Tol

    Tol Registered+

    low_rdr: Do you use the cfl's for flowering too?
  5. low_rdr

    low_rdr Registered+

    Putting the fan right over the exhaust will create the vacuum/increase the vacuum effect :) Making sure the exhaust has proper air flow to do its job is essential, remember how a car will shut down if the exhaust is plugged? If your exhaust on your box doesn't have sufficient airflow, the fan is just a fan pointing at the wall - So make sure it has room to vent. I don't have this problem because I use actual intake and exhaust venting. A forced air intake would also increase airflow. Excuse my rambling, enjoying my last crop :) Okay, so you only need to change a few degrees, which isfine, just moving the fan should do that for you. Remember, if your using foil, and not mylar, your not reflecting just light, but also heat. That's why we use mylar, because of the high light and low heat transfer. You can also use the insulated mylar which many of us CFL growers use, but it won't help your box as much as it helps ours.

    Oscillating fan is the only other thing I can think of which will help your temps.
    • Like Like x 1
  6. low_rdr

    low_rdr Registered+

    Yes, my flower box is 600 watts, my veg box is about 550 watts, my total grow size has increased from my original post, but its about the same, my veg box is about 400 watts, seedling stage is about 100 watts, and 50 watts above the germination/cloning box

    All CFL's - My last harvest did really well, and I'm about 3 weeks from my next :)
  7. Tol

    Tol Registered+

    Saweeet bro! I don't mind the rambling at all since I am trying to learn as much as I can. So by all means...please do ramble on bud. (Pun intended :)

    My reflectant isn't foil but I bought it from the hydro store. It is a real thin reflectant paper almost like gift wrap. It's thin to lessen any additional heat issues. The flooring of the box I found and used my old mylar reflectant i used to use for my car window when I park out in the sun. I haven't found a mini oscillating fan yet which I am still trying to look for.

    Do you have photos of your box I can take a look at?
  8. Tol

    Tol Registered+

    Dude that's freak'n awesome!! I'd love to see some photos. :D
  9. bitemybud

    bitemybud Registered+

    Looks like everything is under control here. Can't wait to see how this turns out.
  10. low_rdr

    low_rdr Registered+

    I've got tons of pics in my thread. Unfortunately during sampling I didn't take any photos of the harvest - I do have some photos of about a week before harvest, but I was low on meds so the butchering went pretty quickly from soil to water to start the process. Anyway, unless I get some really rare pics or I do another log, I won't be posting many more pictures. I'll be doing pics of the new setup on our new room within the next few months, at which point I should be doing about a pound per month, perpetual. I've been trying to select the best yielding plants with the best flavor/effect - Pineapple Express is a good one, but I'm trying some different stuff now, tons of strains. The white widow is going to be great, but its literally 1/4 the size of the rest of the plants and it's 4 weeks into flower, about 12" tall (something wrong there) - Looks REALLY healthy, and the entire top 25% is turning into a bud, but, it's actually lolipopped itself, after I topped it, so its growing 1 decent sized bud, and 1 half sized bud. I'm not impressed so whats really going to suck is in about 2 more weeks when I need that room for light - Short little girl might end up finishing early, which I don't want (you want WW to get nice and crystallized, I still harvest early, but not that early)

    I'm rambling again. Anyway - The strain keeps changing, but I'm working on my own, its going to be pineapple express x big bid x c99 (or white widow) depending on which one comes out the best. The end result should be a decent yield with crystalized nuggets that have a mild psychological effect. Of course it will take several generations of the stable pheno I want, which I'm working on now. I have my PEX standard pheno, I'm waiting on my C99 pheno now, and the only pheno I want from the big bud is the growth rate.

    I'll give you an example of big bud though - I have 1 flowering right now, along with 1 durban poison and 1 WW, they are all about 4 weeks old, 2 weeks into flower. I've had to tie the big bud down twice (HST), both times it had grown into the lights. The big bud is already starting to show pistils, and wrapping its top colas up, so far, they're all about 3.5" and getting larger by the day, last time I checked they were just under 3/4" in diameter. The WW is also showing signs of flowering, and it's 1/4 the size (HA). The durban poison is about 1/2 the size, or so, but very thin compared to the powerbud. The durban poison is coming out kinda like pineapple express with no training (I should have LST'd it)

    All this is with CFL's - I might not have the lumens that an HPS has, but in my footprint, I have the perfect balance, and I;m producing smokable product within 6 flowering weeks :)
    • Like Like x 1
  11. low_rdr

    low_rdr Registered+

    Oh - Wanted to mention...

    I got my oscillating fan from walmart in the automotive section, it is a dc operation fan, but I use a converter. The fan is 120 CFM's, it does a great job, I think I paid $9 for it on clearance, and the adapter is about $7 - So for $16 I got a 6" oscillating fan that does a pretty good job!
    • Like Like x 1
  12. Tol

    Tol Registered+

    Actually...I have just added 4 cfl's to give light under my plants and my temp is up to 99-100degrees now. I've adjust the fan and that didn't help. Should I drill more holes to vent??
  13. Tol

    Tol Registered+

    Holy! This fan is what I need!! Thanks for the tip! I'll head over to walmart and see if they have that fan in stock. that should help cool the chicks.
  14. Tol

    Tol Registered+

    Love the rambling my friend. That is SOOOO awesome that you're making your own recipe. That's all advanced/pro status. I did add 4 cfl lights under the plants and the heat is up to 100 degrees. I turned the fan into the exhaust and that didn't help. I'm thinking i may need more intake??? What do you think? I'll post up a photo from last night. In my garage, it's perfect temp at night with it being in mid 70's but inside the box is up to 99-100. I just can't figure this stuff out.
  15. Tol

    Tol Registered+

    Still need help my friend....
  16. Tol

    Tol Registered+

    Here are the photos i took last night after adding 4cfl's (equivelent to 400w). But i still need some help with the temp issues. :(

    photo 1.JPG
    photo 2.JPG
    Last edited: Jan 18, 2013
  17. Tol

    Tol Registered+

  18. low_rdr

    low_rdr Registered+

    Hey Tol,

    Sorry I don't drop in everyday anymore!

    Okay, yes, increase the size of your intake, and make sure your exhaust is clear on the outside so your not blowing air at the wall - I like the under lighting, but all your doing with the aluminum hoods on those things is holding in more heat, get rid of them, and you'll notice the amount of light you have increases, it's not as focused, but you don't need focused light on your plants, just light.

    make sure your not foilar feeding at those temps, you'll kill them quickly that way, you might also have to look into a cold air intake like I have to do (I vent cool air from outside during the winter, or from an AC unit during the summer)
  19. Tol

    Tol Registered+

    All good my friend. I was asking anyone/everyone who can help with my heat issue. Thank you for your reply. I will drill more intake holes once my light turns on. Im drilling 5 additional 2" holes from the lower front of my box. Ill see how the temp comes out. My silent inline fan exhausts out (using duct) into a carbon filter. I stuck the inline fan and carbon filter on top of my box next to my ballast.

    My inline fan exhausts 205cfm's and my box is about 192 cubic ft.
  20. low_rdr

    low_rdr Registered+

    Whats the size of your inline fan? 4" or 6"? Also make sure you have good airflow going through the filter. When mine is on, I can put my hand up to it and feel a force pushing out just a bit, but close to 2 inches away. So make sure you've got good airflow. If your using a different style of filter, or an inline filter, just insure you've got proper air flow.

    As far as those 2" holes - Why not just cut a vent? You can get the vent covers at walmart or any home hardware store dirt cheap, and it's easy to make a 4x8 or 4x12 passive air intake. I'm using 600 watts (actual watts) in a 3x3x18" box and I NEED a powered intake, otherwise I'll hit 120 degrees (have before) within minutes. However, with my powered air intake from a cool source, my box stays a steady 73 in the summer (from an air conditioner) and it's about 77 right now (on and off window cooling, but the air is temped by running over the lights to avoid any sort of shock to the plants, I think this was actually described in this thread, not sure)

    At any rate, it does sound like your not pulling enough CFM's through your exhaust to expel the heat fast enough, but it does also sound like your not getting the intake you need. Have you put in an oscillating fan yet?

    Just finished up the last of my pineapple express - Got another two weeks for the next crop (bah!) Good thing I've got WW and Powerbud in that one :D I've got Skunk and Critical Kali Mist coming in the next 4 weeks (YAY)... I've heard really good stuff about blue dream - Let me know how it turns out, I might pick up some auto beans - Just found out I'll have my new grow space by the end of feb :D

Share This Page