We stocked 50 sterile Grass Carp in our 8 acre lake because of problems incurred afer the lake was drained for a long period of time. They do a great job of removing and keeping the vegetation to a minimum. The best part is having one hit your ultra light spinning gear while trying to catch pan fish! They have taken everything from bitsy bugs to rooster tails, I know they are not known to strike those lures normally, but ours do. I do not regularly fish for them as a target because of the their place on the pond cleaning team. I had a hard time explaining to my son that the neighbors do not want to see the biggest fish in the lake on the end of his line. They do get pretty big, and there are several different baits that will attract them.
In NC only sterile carp can be purchased, not sure what your state laws are but if you're worried about overpopulation I would recommend that route. Another idea that we used was to add them in stages.
