light distance from seedlings

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TobyTheYiger

New Member
my 1000w mH light is 4 feet from my seedlings(3-4" tall) and running at 50% power ATM, is this distance proper or should it be closer ? and at what height should I increase the %, and/or distance between light source & plants? the ballast has 3 selections 100%, 75%, & 50%. any other tips/advice most welcome, thank you.
 
warble

warble

Well-Known Member
Pictures help. What strain? Are they looking dry? What medium? What's your temp/humidity? If they have made it 3-4" tall with the light at this distance, then they should do alright.
 
nomofatum

nomofatum

Well-Known Member
Review the below chart, note this is for plants with established roots, so back her off a bit more than this shows as optimal.

 
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TobyTheYiger

New Member
I started them under a flourescent for 6 days and got them under the mH on the 6th day(stores where closed, damn holidays :P ), today's day 8, pic below, bit of stretching on some from the fluroscent start,

sunshine 4 mix medium, was dry just watered it, room temp is 25, temp halfway between plants& light 27C (have digi thermostat with outside gauge) dry humidity 22%
quite a few strains: kalshnikova, gods blue diesel, blue amnesia, The Purp, Rainbow Skunk, northern lights, Jamaican grape, Gauva
 

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Hugo Phurst

Hugo Phurst

Well-Known Member
Can you get a smaller lamp? Two small plants like that would do just fine under 100 -150W of CFL's

Good luck
 
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TobyTheYiger

New Member
in a 8x8x8 space ATM those 30 under 500w mH should I increase the wattage to 75% or 100? or when can I go full 1000w? I was told it could burn them if too early
 
nomofatum

nomofatum

Well-Known Member
Aim for the top of the "too far from bulb" zone for seedlings. Once they are fully established I would move to the distance where it shows around 7500.
 
Hugo Phurst

Hugo Phurst

Well-Known Member
From what I've read, you really only need about 50w/sq ft.
So 30some plants take up what, 6sq ft right now? So (IMO) 500w isn't too much...but, seedlings don't need a whole lot of light, they need to harden up a little. I'd hold off dropping the light and turning it up the power until the seed leaves (cotyledon) are pretty much gone.

30 plants is quite ambitious foor a noob (I got 6 in a 4X8X7 and it's full), Good luck.
 
nomofatum

nomofatum

Well-Known Member
I would run it full power up about 32". Sounds like in that space you will want at least 3 1000w fixtures to hit best lighting levels, 4 or 3 with supplemental lighting.
 
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