All, to be honest with you, I think that having 40 HSB in a .25 acre pond is way overkill. Those things can get to 10 - 15 lbs and that's 400 lbs of predators at some point, assuming the F8 giants are even more prolific than known. In a .25 acre pond, I don't think any spawn would ever survive of any sunfish.
40 HSB is what I would do or recommend if I wanted no GG offspring. For that matter no crappie or any other prolific spawner.
If you could remove all but maybe just a handfull, say 5, things would get very interesting... but it's not my experiment, so whatever.
My 7 yo had his first experience with a 1 lb + hybrid bluegill/giant. He was with 100 kids at a youth event. It was the only keeper caught. I'm sure others were swimming, but only the small offspring were caught, beating the larger ones to the bait. Obviously, the guy was not into management, and many folks aren't.
Good luck!
