DIY Cool-tube disaster...why?

Discussion in 'Advanced Growing Techniques' started by tris273, Oct 7, 2010.

  1. #1 tris273, Oct 7, 2010
    Last edited by a moderator: Oct 7, 2010
    I have a 1x1x2meter box, 600w HPS with a 2600ft2/hr (43ft2/minute ?) CFM.

    its summer, round the 30celsius outside during day; with the box wide open the thermometer reads 38celsius, with the light off goes down to 30-32celsius.

    i just bought a custom-made hollow cylinder of pyrex, 1-2mm thick. hooked it up to the CFM hermetically - still,! not even half a degree drop in temperature, the area around and beneath the bulb is still smoking hot!!

    i should mention that the cool tube is open inside the box - one side is hooked up to cfm ducting, the other open so the air 'cooling' the tube is sucked from inside the box.

    why isnt it working? im going mad:confused:
  2. by cfm i mean centrifugal fan, stoner mistake :)
  3. you need to take it back and get flouros and screen or go smaller. Your temps are 100F with the light on and the door open. You are gonna HAVE to think less heat (flouros). I would go P-LL and mount the ballasts outside the room. Anything, you do, you would want the ballasts outside the room. Also, If you are venting in hot air, it will only get hotter. You need new fresh air that is the right temps as well.

    hopefully that will help
  4. #4 tris273, Oct 8, 2010
    Last edited by a moderator: Oct 8, 2010
    i know the heat is a problem - my first 2 harvests didn't have ANY trichomes at all (im guessing the heat baked 'em.) not willing to give up on the HPS :D i need to find out what the problem is - taking my pyrex cylinder tot he growshop so my guy can check it out... if he says thats the problem, ill buy a real cool tube...if my fan ain't strong enough, ill get a better one...

    and if i have to invest in an air conditioner for my meter-by-meter box, so that my harvests become smokable, then so be it.

    the ballast is outside the box...i could add venting and a hole in my box so that its outside air that gets sucked across the tube, but as i said the air outside isn't that cold you know? i dont live in scotland unfortunately
  5. Cool tubes don't totally control heat unless you have two massive centrifugal fans(500+cfm each). They help but are not a cure all and with a 600w hps your gonna want around 1.5-2ft space in between the light and the canopy. Plus you want to have the other end of that cool tube to be hooked up to a intake outside the box intstead of sucking inside the box so it can suck in cool air past it to help cool it. I still use a additional fan to pull hot air from inside the grow area since plain and simple H.I.D.'s generate a lot of heat and reqiure some serious cooling power. Good luck peace:smoke:
  6. I agree that light might be just to much for such a small area and 100F is definetly not going to work since 96F is enough to kill cannabis. Even if it survives your gonna have a raging hermaphrodite, can you say "ace ventura pet detective":smoke:
  7. already happened...put a bigbud female clone in there, LST'ed it to bushy supremeness, saw balls a week later :(

  8. this is not 100% true because i use a 170cfm fan to cool my 400watt HPS light... my set up is carbon filter to ducting to air cooled hood to ducting going up and out the top being pulled through a $100 170 cfm fan from htg supply

    you definetly don't need 1,000 cfm i do not know where you are getting these numbers of 500+ cfm...there is no way a 600 watt light puts out that much more heat

    am i missing something here?
  9. I'm talking about completely removing all the heat. I setup a cool tube and hooked one end up to a booster fan for intake and exhaust was hooked to a 500cfm 6" centrifugal fan. Temps 6" under the bulb were still around 90F and didn't get under 85 until I hooked my second 6" fan up to the intake(that's were I got the 1000cfm:rolleyes:). It was a realtively closed are around the size the dude who started this threads was. Room temp was around 72F maybe your grow room was colder? And yes a 600w hps does put out more heat close to 50% more so yes I'd that's more than just a little more. Now in my case that growroom setup I previously had wasn't ideal considered I should have had the light 1-2ft above the canopy but I underestimated how big my plants were going to get and ran out of vertical space. But you can't tell me your cooltube is cool to the touch with just 1 170cfm fan venting it unless you have a air conditioner pointed right at it.
  10. And my old growroom/bedroom was really cramped so that probably had a additional impact on heating up my grow areas. LOL this was my 420th post:bongin::hippie:
  11. And to answer your question yes your missing a little something a 600w hps uses 50% more power and generates close to 50% more heat.
  12. Damn man that sucks:(
  13. update:

    my growshop guy gave his approval of the tube. my solution is 2-fold:

    1. i pulled the tube away from the bulb - before it "swallowed" the bulb whole - because the bulb sits on a square piece of metal attached to the reflector, if the tube is farther away, then the fan has more area to suck through. this caused a roughly 2degree drop (!!) (from 38 to 36ish)

    2. no idea how i didn't think of this before, but im going to flip my flowering schedule - my lamp has been on from 7am to 7pm. so in addition to the lamp heat, all the day-heat accumulates with it. ill start turning on the light from 7pm to 7am so hopefully the night's coolness will balance out the lamp's heat.

    based on jinn's advice, im also going to distance the plant from the light to ~1.5-2ft.

    i'd love to try your fan modification cousined, but at the moment i'd rather not open up my fan, for fear of messing things up..

    thank you all for your time and your advice! may my next harvest have trichomes!
  14. Why are you fighting yourself. Get a smaller light dude. This is not go big or go home here. It seems like you are growing a little personal. Heat affects your yield and quality. Doesn't it produce withered tricromeless smelless buds?

    Sometimes less is more
  15. you are a wise man, and you're absolutely right, which is why tomorrow im switching my 600w for a 400w. if thats still too hot ill go down to 250w.

    reversing the hours and distancing the tube from the bulb helped a little, but because the box is in my room and i cant sleep with a 600w box shining like its got the 10 fuckin commandements in it, the box stays closed and when i open it at 6am before work its still at 36-37degrees celsius, way too high.

    will update on whether the 400w drops the temp. - winter should be officially starting in the next few weeks so im hoping that helps also.

    let my failure be a lesson to you all - mmj mang is right, sometimes less is more. ive been growing for about 5months now, spent more money than i care to admit, groomed tender seedlings into thick, luscious bushes, and then saw them wither away, either turning out so dry and trichomeless they arent worth the lung damage, or becoming raging hermaphrodites.
  16. Do you have a closet you can use dude? Increasing your airspace will help with the temps. I use 400w h.i.d.s and can manage the temps with two regular box fans and a window a/c. I have my entire bedroom sectioned off with black plastic sheeting and mylar into 6 independent grow rooms. There's barely enough room left for my bed and I'm constantly surrounded by plants and lights. Got used to putting a sheet over my eyes to block out the lights while I snooze.:smoke:
  17. Why? This is like the story of how the anti-gravity pen came into being. NASA spent a great deal of time working on a pen that works in zero gravity. What was the Russian solution? Use pencil.

    I have a 325W CFL grow. Once I make a couple of tweaks I'll be pushing 500W. So far my temps haven't gone above ambient 76F or 24C.

    They make 250W individual CFL bulbs. Put three of these in your box and you have LESS HEAT coming off the bulbs and the same amount of light. Anyone that claims CFL can't match HPS is full of it. Just look at what LED's are able to do. Photons are photons.
  18. #19 jinn420, Oct 21, 2010
    Last edited by a moderator: Oct 21, 2010
    I veg my plants under cfls and flowered them before under cfls and they can not even begin to hold a candle to H.I.D.s. Did a closet grow under a array of 24 100watt equivalent(26w actual usage, 1600 lumens per bulb) totaling 600w usage and 38,400 lumens. Still got hot, used more power and produced 30% less light. The light from cfls isn't as intense and yield is 3x less.:smoke:
  19. #20 jinn420, Oct 21, 2010
    Last edited by a moderator: Oct 21, 2010
    And I'm afraid your the one who's full of it if you think cfls can outdo h.i.d.s. Leds do show promise being able to emit light in specific wavelengths optimal for plants but are still a little bit expensive. And cfls are not like leds just to let you know they're basically miniature h.i.d.s. I'm not gonna go back and forth about something that's fact(h.i.d.s are better then cfls) so I don't have anything else to say besides your wrong.:smoke:

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