Interesting that one of the very first photos shows a plant with hydroton but yet a few roots fall from the bottom and produce a plethora of root mass.
Isn't your argument that the hydroton forces the roots to grow outward instead of just down and that this happening causes increased root mass?
Seems to me that one of the very first posts pics might argue against that point. There is no reason why a plant grown without a medium could not grow the same healthy roots made by a plant with a medium.
You keep saying medium there IS NO MEDIUM.its a root substrate,the medium is either water or air unless its flood and drain,How many guys are doing flood and drain with hanging roots in mid air.Look that up and get back to me.
Good lord man when you get a root mass that looks like that than you will get it.Those roots are from side roots that come out of the net pot.You want the roots to spread out to get as much dissolved oxygen in the water.Why would you not want to use hydro ton or another similar material to get the roots to spread out.This is second grade growing man.Tree and plant roots don't all grow in a clump together downward.In simple flood and drain and any other hydro application people use something to get the roots to branch out.They cant absorb oxygen if there tied up in a clump.
When your roots start to look like centipedes this means all the root tips are getting all the absorbed oxygen and nutrients they can gather,Thats what a root does.It spreads out.Im sorry i am not a scientist and cant give you a more scientfic explanation but i know MY PLANTS NEVER have an issue,Big healthy roots will create big healthy plants.Under current builds there DWC systems with hydroton and every one else in the industry doing it right using something for the roots to spread out and not be clumped into a single wad.
Im sure you dont have to have to use hydroton and let them hang but whats the point?Are you just trying to save a few pennies or asking if it would be better not to use a root substrate?NO i hardly doubt it,In aero you cant use a root substrate because the sprayers need access to the roots.You cant cover them up in a net pot.So comparing the 2 is apples to oranges.Be like saying why not put plants in coco and use an aeroponic sprayer.It just doesnt make any sense.Aero needs access to all the roots.
That pic of the cabbage is a different scenario.Its multiple plants in a tote.the roots will grow together from multiple sources and spread out.
Spread out roots will be better than a single wad of roots.
If you get roots like those you will see the middle of that root ball is empty space.Its like a cone.The air stones sit in the center and the center usually stays hollow and all the outside roots swirl around and stay spread out.