I rescued a specimen of this from a local shop--it was only a couple of thin, fading strands with leaves not much larger than cardimine lyrata, so I wasn't certain if I had the easier H. leucocephela or not. It did not want to stay planted, so I wrapped it around a branch. Now I have to cut it back every two weeks or it will take over the surface. The leaves now range from the size of an American quarter to fifty cent piece! It's gorgeous and one of the easiest plants I have ever kept.
I've had some Brazilian Pennywort now for several weeks in my low light setup (2 WPG of flourescent lighting). I find that it grows quickly but not so fast as to be unmanageable. I've discovered that new plants will grow from a single leaf, assuming the leaf has a small bit of stem attached to it. I've got several leaves floating around my tank at the moment that have started to grow roots. One even has a new leaf growing! This is an easy plant. I'd definitely recommend it!
this plant is indeed a nitrate sucker.. it completely overtook my 75g almost every 2 weeks I would have to trim back... one time I let it go and was pulling out armfuls of it at lengths of over 5ft (in a 4ft tank!)
I got a few strands of this to float in my tank, but ended up having to get rid of them. For some reason my Amano shrimp were terrified of them. Where they would normally be out and about all day, as soon as I put this in the tank they spent all their time hiding. Whenever I'd pull it out for cleaning all the shrimp would suddenly appear and scavenge like mad, then as soon as I put it back in they would disappear again. Really weird.
Grows readily at the surface. But to make it grow in the tank itself, below, I think it requires a lot of lighting. My pennywort lost it's battle against ceratopteris cornuta at the surface. After a long one year battle ceratopteris took over and the once thriving pennywort disappeared. I suspect this plant requires calcium/magnesium because it began starving when put in a tank with soft water, so do the ceratopteris I believe.