Your seedlings just need some good soil, with no additives.
1 bag Miracle Grow Organic Choice Potting Mix
1 bag Hyphonex (spell, look for the black bag)
1 bag Perlite

Divide this into 2 piles, a small one, and another twice that size. The small pile is for your seedlings and young plants. No additives in this one.

Add the following to the "big" pile; 1 gallon of the earth worm castings, 1/3 cup bonemeal, 1/3 cup bloodmeal, 1/4 epsom salt, 1/3 dolomite lime. This will be your "Hot" soil. It's got too many additives for new plants.

When it's time for your first re-pot, put a little bit of "hot" soil in the bottom. That way, as the plant grows it becomes accustomed to the nutrients.

When you repot the last time, before you flower, put a layer of "hot" soil in the bottom of your pot. Then mix the "hot" soil and regular soil 50/50 for a layer, and then plain soil on top.