Anthropic, you talking about this bad boy? In 2014, I found this one in my hatchery pond. We've also seen smaller ones regurgitated by LMB during electroshockings. I never even thought about rearing them. My guesstimate is that the one in this pic was 8-10".
Tracy, a piped raceway would be nice for sure. I'm not sure I would mix tilapia and CNBG though. Tilapia are extremely volatile when crowded, and they'd probably beat the CNBG to death when they're pulled. A piped system might eliminate that problem. I'm no expert on all things related to hatchery ponds, but I know that there certainly comes a point when food costs let you know it's time to get fish out posthaste. Last time I raised tilapia I was right at a 50# bag of fish food every 3 to 4 days. At that pace, an extra month of growth could easily hit $400-$500.
