Overheating?

Discussion in 'Sick Plants and Problems' started by myshtern, Jun 16, 2008.

  1. No I dont know the temperature when the light is on there. The strange thing is how these plants grew. All the same strain, germinated at the same, same light, same water, same soil, but look at the differentiation in the size.

    Think this latest damage is from overheating? I lift the light up a little.
     

    Attached Files:

  2. id say thats part of overheating also ur goin to get dead leaves anyway cos the growth is at the top of the plant im actually gettin dying leaves at the bottom of my plant but thats only the 2 fan leaves that die off anyway and now the second set of leaves are starting to go but my temps allways at between 30celsius and 32 celsius and never goes above that....hope this helps:wave:p.s in the second pic u posted i can see the lights a bit too close for comfort maybe bring it back a bit more away from the plant then take it from there and seee how u go
     
  3. That's not overheating. You've got some serious nutrient difficiencies.

    Look at SmknVTEC's sticky at the top of the sick plant forum. Fill it out and give us as much information as possible and provide some in focus pictures so we can get a good look at the plant.
     
  4. What type of medium: Soil
    What brand and type of soil: Mix of 3/4 Miracle Grow and 1/4 Plain Top Soil
    Indoors or outdoors: Indoor
    What strain: Fast Girl
    How old are the plants: 8 weeks
    What type of lights and how many watts: 400 watt HPS and 2 100 watt CFM
    How far from the lights: CFM are at the base, HPS bulb is about 6" away from the tallest plant.
    What, how much and when was it fed: NPK? No nutrients besides what's in the MG soil
    What is the medium/runoff pH: No PH test
    What are the temps and humidity in the room: I dont have thermometer but I would say it's 85-90 degrees in the room, probably a little over 90 in the plant area
    What size pots?
    Any bugs? none
    Any other pertinent info? I thought it was overheating, I have reflective mylar right around the plants.
     
  5. miracle grow killed my first grow.
    you should have the temp between 75 and 80 in there.
    judging by the size of your plants at 8 weeks, you had some major stunt in growth. might be the miracle grow?

    im no green thumb but i would say get different soil as soon as you can and flush them things.
     
  6. If the temperature is over 85 degrees, that's what's stunting the growth. I'd like to suggest to the OP that there may be more than one problem; the temperature is obviously one if your estimate is correct, and having the Miracle-Gro soil will make it hard to figure out feeding, which can lead to deficiencies or excesses easily. A flush might not be a bad idea, but you'll need to get your temps under control first. And to be able to evaluabte that, you'll need a thermometer.
     
  7. Alright I got a thermometer, ph tester, and superthrive today. The temps are definitely high like I expected it to show. Temps are showing to be around 105 degrees and 35% humidity. However, these temps do not take into effect the wind chill. I have a fan pointing directly at the plants. So I'd say the real temp is about 90-95 degrees.

    PH shows at about 8.3

    I gave all 3 plants some super thrive. Yesterday I turned around the sickest of the plants to face the fan, its already showing improvement. I'll raise the light a bit but hopefully the superthrive will be able to help them handle the high temps.
     
  8. Dear God!!!! It's marijuana hell! Sorry, but I couldn't resist. 90-95 is still too hot for plants, your temperature needs to be 85 or less. Chronitron's link is a great solution, and you need to solve your heat problem fast.

    And 8.3 is WAY too high for MJ plants, you want 6.5-7. You need to get some pH down, or you can use some other materials to lower the pH (try a search for more info, I just use pH up/down to regulate my soil).

    How much superthrive did you add? Just curious, but a little goes a long way, 1 drop per gallon.

    Good luck, and let us know.
     
  9. miracle grow killed ur plant? how much u feed it ??? mines in miracle grow compost and has been since a baby its now 5 inches tall 5 inches width at a temprature of around 30 celcius and its doing fine from what i can see.....:Dnot sure about the humidity or soil temp but i guess ive been lucky so far lol
     
  10. Instructions said about a 1/4 tea spoon per gallon so i did what I thought looked like about a 1/2 teaspoon with a liter of water. Someone told me that might shock them so I'm going to give them another liter right now.

    What's the easiest way to make the water more acidic?
     
  11. With the lights off it drops back down to 80 degrees or so
     
  12. now your HPS is that the kind that is used at shops for flood lights? ( I see the glass hood ) If so those get extremely hot. And with temps like that your fan is just moving hot air around so there is no wind "chill"
     
  13. Sure there is, when air goes from a higher pressure to a lower pressure, it has a cooling effect. Stick your hand out of the car when it's 100 degrees out, that's just moving hot air around just as you said above, yet it still has a strong cooling effect.
     
  14. I'm telling you your factoring in a wind chill that I doubt is even there to "chill" anything. Your room needs to be cool in the first place best way to do this is not by putting a fan in there but to put a fan sucking air in from your room and exaughsting it to somewhere other than your room. I will do this as an experriment with you go buy 20 fans and put them in your room all pointing to your grow area and I will buy 1 fan to blow on my area and another to blow the excess heat out of the room and lets see which one is cooler.

    I used to always see my dad put his fan in his room on a window seal blowing the air back outside was this to cool outside? Nope.

    And puting my hand out of my car going maybe lets say what 10 MPH (think logically for a fans speed) the only cooling I would feel is if I were sweating other than that I doubt there would be any chill factor.

    Remember you are the one with the problem.
     
  15. Fans cannot cool a room, period. Put a thermometer in front of a fan, and one a little ways away from it, and they will read the same, that's just the way that physics happen to work. Moving air moves warmer air away from something and makes it feel cooler, but there's no reason to think that your plants are giving off much heat to blow away in the first place. Also, air temperature flow is based more on temperature itself rather than pressure.

    And myshtern, your whole argument about wind cooling effects
    is beside the point, because even if we took you at your word your temperature is still far too hot. Your plants will not survive well, nor will they produce well (if at all) at that temperature, so you need to figure out a way to drop the temp down as soon as you can.

    And the fastest way to lower the pH of water is pH down, a product you can easily buy on ebay or elsewhere online. There are methods using household products, as I mentioned above, but since I just use the pH up/down I don't use them. Search the site, and you'll find some other methods.
     

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