How far above seeds should I put a 300w MH?

Discussion in 'Growing Marijuana Indoors' started by Agoutihead, Nov 16, 2012.

  1. #1 Agoutihead, Nov 16, 2012
    Never used this high wattage for light above seedlings. Always used four 23/100w bulbs and would always get stretch. So I'm trying to avoid that this time to get healthier seedlings.

    So how high above the coco should I have the 300w MH bulb hanging?

    The seeds will be put directly in coco to germinate.
     
  2. #2 BYOweed, Nov 17, 2012
    [quote name='"JohnnyScience"']Never used this high wattage for light above seedlings. Always used four 23/100w bulbs and would always get stretch. So I'm trying to avoid that this time to get healthier seedlings.

    So how high above the coco should I have the 300w MH bulb hanging?

    The seeds will be put directly in coco to germinate.[/quote]

    I put my 400w 3 ft away for the first 2 weeks, then down to 2 ft until 1 month. Then, as close as I could, which is about 1-1.5 ft.

    To help keep the soil moist for germination, I put a small bag over top of the container to keep in some humidity. Doesn't need to be airtight
     
  3. #3 CBM, Nov 17, 2012
    Byoweed is right, try and lower the light gradually until the sprouts get settled in. Putting it to close will stunt them, as it will stress them out.

    The type of hood you have is also a consideration. If you have a cooled hood then as they get bigger you can have it as close to 12inches. If its a standard bat wing keep it a min of 18-24 as they get older.

    And if you get some stretching, lower it down too but watch the temps. Keep it around 75deg or under, else this will slow there growth.

    GL buddy!
     
  4. #4 BYOweed, Nov 17, 2012
    [quote name='"CBM"']Byoweed is right, try and lower the light gradually until the sprouts get settled in. Putting it to close will stunt them, as it will stress them out.

    The type of hood you have is also a consideration. If you have a cooled hood then as they get bigger you can have it as close to 12inches. If its a standard bat wing keep it a min of 18-24 as they get older.

    And if you get some stretching, lower it down too but watch the temps. Keep it around 75deg or under, else this will slow there growth.

    GL buddy![/quote]

    All great info, however plants will be fine with temps up to 85F
     
  5. #5 CBM, Nov 17, 2012

    Ive always had trbl with anything above 80deg, which caused slower growth. At 75 it seems to be the sweet spot for me. I try not to get past 78 though.
     
  6. #6 BYOweed, Nov 17, 2012
    [quote name='"CBM"']

    Ive always had trbl with anything above 80deg, which caused slower growth. At 75 it seems to be the sweet spot for me. I try not to get past 78 though.[/quote]

    That is just about the perfect temp for cannabis
     

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