i have a similar issue. but mine is way past your stage. i think its because my soil is too acidic. i just watered with some lime tainted water (lol) and im waiting to see what happens in the next few days. i suggest not feeding them anything. you will only make it worse. your plants dont need any food till the cotyledons fall off. all you will be doing is making it worse.
http://www.icmag.com/ic/album.php?albumid=763&pictureid=16744