First 2 leaves (spear leaves) turning yellow. Sign of nutrient deficiency or..?

I'm at that same point. I have seedlings with only two sets of leaves in 3 gallon bags. I have to water them as if they were still in party cups. I water half around the root zone and half outside of that. I check and water them every day or two. I have my reasons why I have seedlings in the full size bag. If you are curious, check out my indoor grow log.

hey just an update, all the plants seem to be doing ok now! whew, i thought i lost almost all of them. i just gave them some very diluted fish fertilizer (holy crap that stuff STINKS) a couple days ago and it appears they've picked up the pace quite a bit too. it's cool watching them grow up, hopefully there will be a couple females! thanks again guys