The point isn't necessarily how much SPACE you've got, but the ability of your lights to penetrate into the canopy.
A tall plant under lights isn't efficient, because the lights can only reach a few inches into the plant, and the rest of the plant just sits there taking up space.

The Canna nutes are beautiful and very forgiving. I run them in my hydro system, on *gasp* CITY WATER!!! hahaha. How great is that. Never tried the Terra series but judging by the quality that I've seen I'm sure it's good.