tilapia are not my fish of choice. I prefer fish that will survive my local climate without requiring heating to keep them alive (let alone eating or growing.)

I've found that in my systems the catfish grew just as fast or faster than the mixed gender blue tilapia and the catfish grew much larger. (easier to clean one catfish instead of 4 tilapia for a meal.) Anyway, now I'm growing some bluegill so I'll be able to compare their growth rates to the tilapia, if any of them are big enough to eat by December then I'll count them just as fast as my tilapia had been.

Only drawbacks is catfish and bluegill are not that interested in eating lettuce scraps.