Light Height Adjustment

Discussion in 'Advanced Growing Techniques' started by vernon_dozier, Jan 25, 2009.

  1. 1st grow - 400w MH - Ebb & Flow

    After my seed germinated I put them in rockwool in my garden. I had the light hieght at 36 in because I was scared it would be too much for them just starting out. It's been a week. I have no experience but the taller ones are looking like they are stretching. So the last couple of days I've been moving the light down a couple inches a day.

    Today I run across the mh chart in the "Charts" thread and it was saying optimal is at most 17 inches.

    Now the question: How far can I move it down per day without shocking them? Or is something I should even be worried about?

  2. I went about 6" a day with a 400HPS. Jumped alittle more than that once and got a little heat curl on a 10 day old. Just keep it as cool as you can.
  3. Thanks for the quick reply Farmer.

    I'll go 6" per day, keep an eye on them and that should put me where I want to be in 3-4 days.
  4. I was just about to ask the same question. From the chart, it appears that the middle of the optimum range is 10-11" at 400W MH. I have the Sun System II reflector that comes with a tempered glass cover. Would the measurement be taken from the glass or from the bulb?

    Anyone have any recommended heights for this type of system?

    Thanks for the thread!
  5. #5 Bubba P, Jan 27, 2009
    Last edited by a moderator: Jan 27, 2009
    :D Hello everybody
    I'm running a 1000wt hps on 12 hybrids, I have them at 27in. could i go lower?:D
  6. Hey Vern! your a football coach right? hahahaha

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