yes the white tail is the tap root.
plant the sprouting seeds with the taproot pointing downards into the soil.
Some strains are slow starters, so patience is the key...The one strain i have bred took hella time to break the surface of the soil and to get started with decent growth.
just make sure the soil is kept moist, NOT WET, put them somewhere warm and fingers X'd they'l poke their heads out in a day or two.
If you have some superthrive, add a drop to their water, and that'll help the seedlings if you've stressed them or if they are a lil unhealthy since you moved them.
Next time you water your plants, catch some of the excess 'run-off' water that comes out of each of the pots, dip the litmus paper, and compare it to a PH scale to detemine the PH of your soil + water Combo.
Adjust the PH as necessary.