ok so I have this to choose from
dwarf sagittaria (i got a recomm. for this, any thoughts from you guys?)
or I can stick to my crypt wendtti wannabe carpet lol.
Dwarf sag will grow taller than something named dwarf should.
C. Parva is the slowest grower of this group and will stay low, i've had 3 in my tank for as long as i can remember and they haven't really grown much at all.
i have no experice with tenellum, but i had another Helanthium that grew out of control on me.
and i have no experience marsilea but i'v heard good things.
the crypt wendtti will grow above the suface and taller than i think you want a carpet to, but trimming will keep it nice a bushy.