The pros will be along with good advice. That is a lot of CNBG for 5 acres. How big were they when stocked? Are you feeding them? I'm not familiar with CNGB but reg bluegill don't have to bee too large to start spawning, which means you could have a population explosion in a year. Personally, I would try to get the numbers down. I'd try to find some LMB large enough to eat some of the CNBG and probably trap some too. They should grow pretty quickly if you are feeding them and provide you, and possibly friends, with some decent table fare. A few smaller LMB would work on the FHM but I doubt they'd be a problem. You can always take out a few LMB when the balance gets where you want it. It seems keeping a pond in balance is one of the biggest challenges.