Most of our plants grow in the three veggie filters.  Parrots Feather grows in pots in our Veggie Filters.  In the Spring, we pull clumps of Parrots Feather out of the Veggie Filters and throw it into the main pond.  The fish use it for spawning.  The Parrots Feather floats on the water and grows like crazy until in starts getting hot in June,  when it starts dying back.  We don't have water lilies because the Koi tear them up.  The workhorse plant of our veggie filters is the Korean Sunrise.  The fish love to eat the algae that grows on the walls.  They line up like they're at a buffet table.  We use a rake to clean the string algae off the waterfalls and a skimmer net to help control the duckweed.