Water Celery is a mainstay for my veggie/biofilter. I have the regular and
the variegated, though for me the regular( all green )seems to grow much
more vigorous. It will grow everywhere even on the ground, wherever it
touches. I have had so much excess I pull it up and give to a friend to
feed his ducks. They love it. Its roots get very thick and form a dense
matt when in the veggie filter. Mike