how far should my light be away from plant

Discussion in 'General Marijuana Growing' started by happydave, Oct 5, 2009.

  1.  
    happydave

    happydave Active Member

    i got a 400 watt hps
  2.  
    DubRules

    DubRules Well-Known Member

    12-18".
    put your hand on top of your plant and hold it there for a few minutes.
    if your hand gets hot, it's too close.
    KaleoXxX likes this.
  3.  
    KaleoXxX

    KaleoXxX Well-Known Member

    i was gonna say, do the hand test, but this dude beat me to it.

    if you put your hand at the top of the plant and can fell the warmth, but not heat, of the light, your at a good distance
  4.  
    southern homegrower

    southern homegrower Well-Known Member

    i keep my 1000w at 18 inches
  5.  
    Johnnyorganic

    Johnnyorganic Well-Known Member

    HPS can produce intense heat especially in an enclosed space with mylar. Akin to an Easy-Bake oven failing proper ventilation.

    The back of the hand test is a very good indicator but definitely no closer than 18".

    Good luck and good growing.
  6.  
    bigtomatofarmer

    bigtomatofarmer Well-Known Member

    I also recommend getting a cool tube.

    [​IMG]
  7.  
    hershy62

    hershy62 Member

    How high should i keep my t-5s from my veg plants thanks for any info right now they are 12 inches and dont seem to be growing fast enough
  8.  
    jawbrodt

    jawbrodt Well-Known Member

    ^Man, bring those lights down, as close as possible without touching the plants. At 12", the output reaching the plants is VERY low. I have a light meter, and anything more than 6" is almost useless.(like 1000 lumens) I try to keep mine within 1" which is tricky because they grow really fast and I have to watch so they don't grow into the bulbs. On a good day, i have to move the bulbs twice because they are growing so well. :)
  9.  
    hershy62

    hershy62 Member

    thanks ill lower them down closer
  10.  
    zip

    zip Active Member

    mine were too far away and moved them down and noticed a difference immediately
  11.  
    resinousflowers

    resinousflowers Well-Known Member

    10 - 12 inches should be fine from my own experience.

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