Question about feeding?!

I im in the middle of my first grow and i have used this soil (on the pic) and mixed little bit vermiculite and perlite.

I have given this plant only water, exept one time i gave her a light mix of water and seaweed extract.
Now its been 13 days since first sprouting. My question is, when ill have to feed her and wich nutrients?
Is something like 4-1-2 ok for the first feeding?
And isnt my plant too liddle for 13 days? Could it be because of light? i have a 5500 lumens fluorescent bulb.

Its a little on the small size but looks healthy. At that size I usually have two 100 watt CFL (23 actual 5000K temp) close in proximity within 1" of the seedling. I also have lights on 24/7 to speed up development. As for nutrients dont do it! I usually dont start grow nutrients until 30 days. 3 weeks at the least! Then only 1/4 reccomended strength every other watering. After you do that dowage for two or three times and all looks health, up it to 1/2 strength and hold. 4-1-2 is fine for grow nutrients...mine is 3-1-3.

What Smokenpassout said is right on.