David:
I agree with Bill on the options that you have with the forage pond. Just remember that the species of Tilapia that you stock in Texas don't survive water temps much below 60�F range and will die when water temps drop below 50�F or so.
My pond was (and still is to an extent) forage light in regards to LMB. I stocked non-feed trained LMB in the beginning, but when I noticed them eating themselves out of house and home, I stocked 39 feed trained LMB that I tagged and have a standing rule that
every LMB not tagged comes out, no matter what the size. 2" or 5#, if it isn't tagged, it comes out. I don't have a lot of cover in there for the forage fish to hide in, so the LMB eat a LOT of them. Too many, I'm afraid. That's why I am switching over to feed trained LMB. I can cut down on the amount of forage fish they eat with pellets. They aren't all female, but as of last year any male seen on a spawning bed gets removed. Unfortunately, they still somehow manage to pull off a spawn and the YOY LMB still eat a lot of YOY forage fish.
Take a look at this relative weight chart. Pay attention to the length/weight of the LMB.
http://www.fish.state.pa.us/images/pages/fishin1/weightlength3.pdf Look and see how much a 17" to 18" LMB should weigh.
In October of 2012, I removed a LMB that was 17.5" long and 4 1/4#. (No tag, so it was removed). I could not tell if it was that size because of learning how to eat pellets, or just because it had plenty of forage fish to eat. The previous year I had added over 2,000 2"-4" BG to the pond, and annually stock 40#-50# of Tilapia along with feeding the fish in the pond. The year before that I also added somewhere between 1,000 and 2,000 2"-5" BG to the pond.
It's taken me 5 years to start to rectify my mistake of having too many LMB in the pond for the amount of forage in it. It's taken a combination of adding a LOT of forage along with removing a LOT of LMB. You have the opportunity to shave 4-5 years off of your learning curve if you jump on top of the problem now.
From your responses, I know you don't want to hear this, but to achieve your goals YOU HAVE TOO MANY LMB IN YOUR POND. Let me repeat that. YOU HAVE TOO MANY LMB IN YOUR POND. Living in the climate that you do, you have the potential to grow much larger LMB in your pond than we do up here if you get the right genetics in there. Do you know if the LMB you stocked are Northern strain, Florida strain or F1's?
If I was down there and that was my pond, I'd get all the LMB out of there before they spawn this year and restock with good genetic feed trained LMB, going with straight females if at all possible like Bill said. If done right, I'd bet you could be catching 4-5 pound LMB in 2 years or less.
By leaving all those LMB in your pond you will run into a wall in regards to carrying capacity in your pond. Remember, a pond can only support around 100# of LMB per acre, maybe a bit more if they are pellet trained and you also supplement their forage fish food base. But, remember they need Oxygen to survive, and the more pounds of fish in there, the more O2 they need.