It’s “soilless”. My talented grower partner uses a medium of 2:1 coco coir and perlite. No nutrients and excellent drainage.
Basically you pour nute through the medium until slight runoff. Occasionally flush with some water. Big advantage is you have no worries about selective or differential nutrient use because every watering us fresh complete nute.
Look up Gen Hydro’s “drain-to-waste” or DTW nutrient schedule. I’ve done soil, I’ve done hard hydro, and this method seems to me to be an excellent middle road between soil and reservoir hydro. Jmo