A,
I grow mine in a mix of LFS,Peat, and Perlite, might be some vermiculite in there too.
You'll see there is plenty attached to it.
I grow it as an affixed aquatic as well, atleast I used to.. Been running short on time lately, so they have been drying up abit.
It has spread like a weed for me, tho the leaves don't seem to be all that long lived.
And just like everyone else has said so far, I have no idea on how to get it to flower. This, U. tricolor and U. reiniformis (Feeling lazy hope I spelled that right) are the 3 species I have that haven't flowered yet.