Yellowing as shown in your pics is completely normal. Those bottom baby leaves fall off just like peoples baby teeth fall out. I would not be giving them so much ingredients in their nutes. Don't get so technical man. At that stage I switch to about 1/4 strength veg nutes, then gradually increase to full strength or so. You don't need anything else if you have good nutes like Fox Farm's Grow Big. If anything, I would probably add just a couple drops per gallon of Super Thrive or Liquid Karma, but your crop will turn out fine without anything but veg nutes. I get a little more technical during flowering, but not much. Just bud nutes, and a boost or two.

Also, have you ever thought of making a cheapo airocloner and keeping a couple mothers? Much better results then rooting seeds in peat pellets. You can use scarification (search) to make massive amounts of root sites, and you can just lay the roots in the pot with some capilary matting (like a wick), and fill in the pellets around the roots. Good luck.