Ozark,
First -- a hearty welcome to Pond Boss. It is a great place to get answers to the types of questions you've posed.
Your pond sounds very similar to mine, except that mine is only about 0.6 - 0.7 acres, and I don't have fatheads. Otherwise, a very similar history, and about the same age. We've owned this pond for a little over five years.
When we bought the place, the pond was overrun with huge catfish that were a serious problem. They were digging caves in the side of my pond. They ate everything in sight. But, the crappie and bluegill were pretty healthy. The bass were so-so.
I don't remember how many we pulled out, but it was somewhere between 15 and 20 like this fellow:
I was really down on the channel cats. But, after attending the first and second Pond Boss conferences, I was convinced that I wanted them back in my pond -- but they had to be controlled. I now annually stock 15 to 25 channel cats as 10-12 inch "put and take." I put in numbers I know we will pull out in a year's time. This was a 10-12 incher after about a year in the pond:
They are certainly a top predator and compete hard with the bass. But, I manage my pond primarily for big bluegill. The catfish are a lot of fun, they provide great meals, and they do a good service. Similarly, I put trout in the pond during the winter for the same purpose. I keep my bass very over populated and hungry. Consequently, they don't get very big.
This is what our bluegill and crappie look like:
The typical bluegill that gets pulled out is between 9-11 inches, with a few close to 12. We've got a healthy spread of Year-of-Young to 12 inches. We keep virtually no large healthy mature male bluegills, and we throw back most females over 10 inches. Every other bluegill comes out.
The typical black crappie is 12-14 inches, with a few 7-8 inchers. None ever go back in. We don't get a lot of them, and we usually only get them in late winter and early spring.
I give credit to the bass, the catfish, and the trout in helping grow large bluegill and crappie.
Your pond may be overstocked, but start a goals and management plan now. Keep good records, and within about two seasons, you should have a trophy pond.
Good luck,
Ken