Tropicanna Cookies x Purple Punch - Custom Living Soil

Ive put those seeds directly into my substrate, like i always do, on the 10th of August. Exactly 72 hours later, on the 13th, they all popped up and showed their germination leafs. Substrate is a mix of peat, pumice, sand & vermiculite. It is my first time growing in a substrate which is that poor in nutrients. Normally i would use my homemade living soil, but ive had a major fungus gnat infection which im trying to eradicate at the moment which is why im using this. But it is also some kind of Experiment i am doing, as i have not seen many growers use "hydroponic" /nutrient poor substrate paired with the "living soil" approach & organic feeding. So be hyped with me! We are planning to repot the 4 strongest plants into their "real" home after about 14 days of vegetation. Their home is gonna consist of 2 substrate levels in a 40l container. The bottom 2/3 is going to be the substrate ive used for germination, which i mentioned above, the top third is gonna be a layer of my homemade living soil. Ive set their homes up already a week prior to germination and moistened it to let it cook together, so the living organisms could colonize the bottom subtrate before transplanting. I am going to feed my plants purely organic/natural material by top dressing with different amendments and by watering with homemade nutrient ferments.