With no predators, you will have to fill that role. Perch will stunt because of overpopulation, so you and a fishing rod will have to keep them in check.
Grasshoppa you have to think out of the box. As Kurt said it is possible to raise perch to large size without a predato as Bill Cody does. Other than using feed trained perch that are primarily females and periodically stocking new ones, Bill also removes all the perch eggs he sees and he has a slot limit. Bill?
Here is a picture of some perch his guest is holding out of Bill's 3/4 acre pond. I hope you don't mind me posting this picture Bill.
