Will the tote that the roots are in is something like 22 gallons, I would say that I have about a foot from lid to bottom. And yes you are right about the roots suspending, and because of the way I designed the system there is not really any "runoff" it drains right back into the res, but I know what you meant. I read on one of the links I posted that one of the guys was getting 2 full CM of vertical every 12 hours. The roots on the other hand really should not get to big. They are supplied with everything that they need and do not need to go looking if you know what I mean.
These are what the roots should look like, little pom pom roots is what we call them. Once again this is not my picture or my idea, but I think I am the first on this site to mention anything about it.