hi buddy....
i gave here a recipe and i show with pics how i do the 3 layers in pot 👍 feel free to take a look
growdiaries.com/diaries/33542-purple-haze-the-7-chakra/week/159076
for the second layer cut with perlite/vermiculite/coco (as u prefer) around 40% for 60% of your mix...
firt the first layer in footprint use an super aerated mix dedicated to seedling.
why all that thing.... autos are really sensitive (really different than photo on that point) and due to their very short cycle most of the time they don't need a lot of N in the veg stage.....but more and faster u will developp root better and bigger will be your plant.... that why cutting with a neutral media ensure a fastest root's development.
with this recipe you can begin to nute with light amount of blooming product in the second week of flo...and increase slowly to the 4th week then you can give pk to the flush
happy growing dude