no worries, 'sall good... I never thought about it that way though, I agree though that cubes are just "smaller per unit volume".
To be honest I've never really understood the distinction of a nano tank versus not a nano. I guess a 5g tank has different considerations than a 500g tank, so I see that there really are two distinct categories, but I've never really thought much about where the boundary really is. A 5g is easy to classify and a 500g is easy to classify but how does one define say a 50g?