hey De Plano,
yah its not quite watercress season, so wont be able to get any anytime soon. but if/when i do, i will try it, as apparently (from reading on the web) that its best to let it float atop the tank as the leaves grow out of water, and the roots will hang down. the roots that hang down can be eaten by the fish (apparently they like it) hehe so i guess its more of a fish food than decoration eh?