Get you some 4in pvc and 4 90 degree elbows and make a square. Then go get some 1/2 square wire (the kind rabbit cages are made of) and wrap that around the cage and cut a bottom and wire it all together.Tie a rope to it and throw it in the pond.. Give the turtles a couple of days to get used to it and they'll think they have a new sundeck..Once they fall in, they cant get out and you can retrieve it daily to get rid of them. I bet I pulled 100 turtles out of my pond last summer.. I got to go put it back in this week, I'm getting overrun AGAIN this year..I have too many other ponds around me to erradicate em!!