This is basically hydroponics. And by "basically" I mean "exactly". Replace the soil with an inert, porous medium like hardened clay. And if you aerate the wate

This is basically hydroponics. And by "basically" I mean "exactly". Replace the soil with an inert, porous medium like hardened clay. And if you aerate the water with say, an aquarium pump/stone, you don't even need to drain it...