Nelumbo nucifera; The Magnificent Lotus!
This is it!  If you want to win the, ‘I have the coolest
water plant” contest, then here is your winning entry!  
Contrary to popular belief, Lotus are easy to grow… but
their main problem is, they’re easy to grow!  What?!?!?!
The fast growth quickly leads to overcrowded pots or
ponds usurped to the needs of the plant, and few would-
be growers want to contend with the muck and
‘ickyness’ that the Lotus requires.  Also, although the
plant is easy to grow, in Hawai`i it’s actually difficult to
get it to reliably flower naturally.  The plant can be
forced to flower using artificial means but we view that
as little more than cheating so we don’t do it.  If you get
one to flower, then you’ve earned the PhD in flowering
water plants… the spectacular Lotus!