Water sprite is very easy to grow, either in the planted form or floating. I do both in fact! I like to plant a few springs and when I am ready to trim them, I float the trimmings to add surface cover for my fish. If I want to plant more, I simply take the floater with the best root system and plant it.
I have a HOB/power filter and the current does not seem to bother the floating ws much. Mine grows well at approx. 1.8 WPG, with a not very efficient DIY CO2 (although it grew well with Excel also), and doses of Flourish and KNO3. My shrimp love it!