I would like to purchase some duckweed to start a duckweed growing tub to feed our fish in the aquaponic system we are starting.
Bonner County Idaho
I'm not aware of a company that sells duckweed and although duckweed is eaten by certain fish species, it does not provide all the nutrition a fish require. I recommend purchasing fish feed specifically formulated for the fish you are growing. However, if you still want to grow duckweed, in a few months when temperatures are more summer-like find a still water body and you will likely find duckweed that you can take home to grow.