Whenever I start plants from seeds, I start with a cup about half full of coco/perlite, and add more as their spindly little stems grow. I am not sure if it is a good way I grow them, but that is what I do.
Don't you just love it when a plan comes together. Or...falls apart? LOL. I feel your pain. This grow I have had to do battle with spider mites, thrips, and even yellow mushrooms. WTF? Yes, yellow mushrooms.
I bought a little lime tree from Home Depot and stupidly threw it into the tent and it really messed everything up!