10 to 15 lbs of 5 inch or larger tilapia should do the job.
Eric, I think I should correct you on this suggestion. Pound of tilapia for stocking is based on an 8" average sized fish--or roughly 3 per pound. If using a 5 inch fish, it will be more fecund than a larger one and you would actually want fewer fish or the same "pound" equivelant number stocked. ie 30 5" fish would be the same as 10 pounds of 8 inchers.
