How Long for secondary leaves to form?

Ok i have had my norther lights sprouted for 3 days and the secondary leaves are still tiny little nubs. All that seems to change is the plants stem gets longer and longer and its under a 400w mh so i cant understand why it would stretch so much. The light is about 2 and a half to 2 and a quarter feet from the plant to avoid burning it. Also the stem is about 2 and a half inches to 3 inches long. Any advise would be very helpful.

The roots do their thing first!

I know the roots start before it even brakes the ground but i am looking for a general time when they produce there secondary leaves. As my last few batches seemed to have them out on day 2 - 3 not fully formed but about half way done by then while this one still has its 2 little embryo leafs and the primary leaves are 2 tiny nubs.

Have patience. In the mean time, add some soil to the cup ( I'm assuming here that you have your seedlings in a smaller cup, not their final pot ) and bury those stems until 1/2" below what leaves you have. Roots will grow off the buried stem.

Ok and yea currently there in a pot about 6 inches deep and 4 across i though that would be more then big enough to start them in and keep them there till there on there third or forth set of leaves then transplant into there final pot a big 8 gallon pot.

give her time my good friend she does what she needs to do b4 her veg starts just give it time

Temperature in there? Try not to let it get much over 82, lower temperatures are ideal.
Get a temperature reading from where the plants actually are, or at canopy level.

So long as heat isn't an issue, you should begin to bring the light down. A foot and a half shouldn't be too close, so long as it remains cool enough under the light. If it was getting enough light it wouldn't stretch very much. I totally prefer T5's for seedlings\young plants for these reasons, though.

Media\details? Watering properly?