I am keeping this plant outside in a 10g aquarium and it is by far the fastest growing plant I have ever seen. I got it 2 days ago and it was like 3" each and now they are like 9". Amazing that there was a day of it being dormant but it really just takes off.
I looooove this plant. The pictures to the left are of submerged growth. Its a very dainty and feather plant. It grew in my low tech low light tank. But very very very very slowly. Like a centimeter a month. In my low tech high light tank it grows about an inch a week. Which is just fine with me. I'm certain that the addition of CO2 could turn this into a fast growers. And probably gives it a more compact appearance. Over all a very very pleasant plant.
I have a seen this plant locally at a place where they sell it for ponds. They were submersed but a lot of them grew to the point where a good portion of their stem was emersed and healthy as well. Photo at left is emersed growth like I see in a pond.
I have this plant in my ponds and one of my aquariums and I think it looks great. It quickly grows roots and looks good hanging over a waterfall. When I trim the emerged form in my ponds, it will branch off with many new stems, making it more dense and cover a greater area.