2 week old plants

Hey I was wondering does anyone know if you can give your young plants anything at all to help speed up the process or are they simple to young to do anything besides water them? I have a five two week old plants under a 400 watt hps system and they seem to be growing really fast and look super healthy. Can I maybe give them nitrogen some how? Ive only done one grow previously to this one so any info would be awesome.

no you cant give them anything to speed it up.....how hot is it with that 400 watter?
if it is over 90 it will slow growth...happen to me and it sucks hehe, wat is the temp like

at 2-3 weeks i usually mix a watered down nute solution to give my plants. i either cut it in half or a quarter. so if you got to mix 1tblsp nutes to one gal water, i do 1/2 or 1/4tblsp per gal until they get bigger