I would not put anything in the supposed to be genetic pure FLA pond. You might regret that for a long time. Once the FLA get sexually mature, I had 8" breed this season, they begin to look different. The females start adding girth, if you get two fish different sexes side by side it is easier to tell. I'll also milk them in the Spring. That is a surefire way and I have no morts doing that.
I always keep as many ponds as I can with my pure strains for resource ponds. These are in a patrolled gated community on private property so no knuckleheads can screw me up and put bad or undesired fish in. They have remained single species ponds for over a decade now. They are one way ponds, fish come out, nothing goes in. Brood ponds. I wish I had more but I am experimenting with drawdown ponds now.
My fish are the same way, the larger fish get harder and harder to catch. They don't get that big by being easy to catch or stupid. So I just recruit new classes with larger numbers to hopefully boost my average weight and size average per fish caught. I pretty much adhere to Lusk's guidelines there. But in my humble opinion, it all starts with genetics.
