I'd say the long leaf dwarf sag would be ideal for this unless you have a tall tank. Vals do it, but are so thick, I'm not a fan. dwarf sag is thinner and more elegant. Also grows great.
Except most sags (dwarf ones at least) do not reach to the top of the aquarium unless you have a fairly short tank. At least, not IME...I've never heard of a 'long leaf' dwarf sag so that may be why.
Thanks for the pics JP, those helped alot! The vals do what I was thinking, and trying to describe wonderfully! Seeing the pennywort, I think that might do what I want even better than what I was trying to do. I always thought pennywort stayed low... lol. How quickly does it grow? Does pennywort do best planted directly in the substrate, or attached to something?
I have planted pennywort directly in the substrate and it grows pretty quickly without much care IME. Granted, it was only a 10 gallon tank but it should grow higher.
So, just to make sure I am seeing this right, pennywort will pretty much grow up, until it reaches the surface, and then it will pretty much grow sideways? Or does it just grow up, and will only spread on the surface as much as it has spread on the bottom?