A number of years ago, I'd fish a farm pond That no one fished for bluegills. I'd harvested a bunch of smaller ones several times a year. With each year the average size of bluegill & crappie increased. The last time I fished this pond, the size of the bluegill's had went from 5"-6" to 8"-9" in a time spand of 4 years.
I don't have a pond, no experience with raising them. I do fish a public lake nearby that was drained a few years ago, not sure exactly how many. It was re-opened for fishing Oct of 08. I learned of it spring of 09 and started fishing it. Almost everything I caught was 7 inches. The ones this year are 8 to 8.25. This is a 150 acre lake and there is no feeding program. This one came from this lake. They don't seem to have slowed down in growth from when it re-opened.