How would those requirements change if you were raising tilapia instead of BG?
I'm certainly no expert, but I've raised my share of fish.
I can't think of any requirements for tilapia other than a correctly sized raschel weave net, and a gallon of clove oil to semi-sedate them, as getting them out of a pond is laborious at best. I had one of the biggest tilapia breeders in TX tell me the best way to raise tilapia, is to throw 5 pounds in a pond and walk away. Other than feeding mine, I did the same, and the pull out weight was mind boggling to say the least. I'll never do it again. If I had to pay $1 for every cuss word while seining them, I could buy a new boat.
This is no help, but my Coppernose found their own best places to spawn, and repeatedly spawned in the same hard bottomed beds. My plan after my hatchery pond clean out, is to do the same, then fill in the preferred existing beds with gravel. That does seem to help the numbers. The spawning depth fluctuated with clarity and water level, and there were beds in about a 5' depth range.
Just a few things to think about. The shallower the slope, the easier it is for GBH and great white egrets to whack your spawning beds. I had set bird netting out over the preferred bed areas to protect mine. Concentrate on your water quality, and invest in a quality water testing kit, not a swimming pool kit. If you go with aeration, then have a backup plan prior to oopsy's. A fish kill due to low O2 and high fish volume is not the time to be trying to figure out a solution. I don't aerate, but I do have a PVC venturi aeration rig for my 3" pump ready to go. $10 worth of PVC, and a palm sized piece of thin aluminum is all it took. It takes less than a hour to set it up, and if the pump's already on it's dedicated platform, then it takes about 1 minute. Figure out how you're going to get the fish out, how you're going to hold them at the bank, and how you're going to transport them if needed. Moving fish can be stressful on them, so always go with oxygen, not air, and get some Pentair oxygen diffusers and an a O2 bottle. O2 bottles are pretty cheap on Cragslist.
Finally, small fish are always happier in water. DO NOT load a dip net full of 2" to 4" fish. You can crush or suffocate the lower half of the fish. Unfortunately, I can confirm this.
