How to tell how much light to give seedlings and when to increase?

Hello,

My first grow I did with clones and now I'm starting from seed, i just put in a CFL for them right now, most are about a half inch, two are 1 to 1.5 inch. Wondering when its safe to bring in my 400w MH, maybe right away if its several feet above (could go to about 4.5' above)? How can I estimate how close they can handle this early? (i'm assuming getting it as close as possible but not to burn could be too much for a seedling)

Wait until you see the 2 sets of the real leaves popping up. If you go to big to fast it slows rooting to focus on growing, but generally once its up to that second tier its good for the big bulbs. Hope your ready for the big plants.

wilsoncr17 said:

Wait until you see the 2 sets of the real leaves popping up. If you go to big to fast it slows rooting to focus on growing, but generally once its up to that second tier its good for the big bulbs. Hope your ready for the big plants.

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Cool sounds good, only a few of them have opened up and started showing the two small normal looking cannabis leaves in addition to their 2 initial baby leaves. I'll probs throw the 400w in sunday if they've all gotten far enough