Here in MS, triploid grass carp are commonly used to control grennery
in our ponds.. They do the job wonderfully. They eat most green in
their youth and slow up as they age. Two to four per acre seem to do
the job. They get to be HUGE. We have a new 1 acre pond and will be
stocking with blue gills this spring, bass in the fall and grasscarp
in late spring.

Our home pond is 4,000 gal. The koi in the main pond LOVE the
duckweed and eat it like desert whenever it comes down from the berm
ponds.

Jim