First we're glad you found us!

Parrot's feather is a real pain to get rid of. I pulled all of mine
out of a small bog garden and the stuff was still
growing in the moist compost a year later!!

Go here --
http://www.ecy.wa.gov/programs/wq/pl...s/aqua003.html
But you'll need to find what is legal in your state.
I would contact the county extension office.

good luck and we're happy to have you here!
k :-)
http://tinyurl.com/6bguh ~ new pond keeper info
http://tinyurl.com/yp64db ~ slide show of pond