Based on my experience (one growing season in three ponds), you need predators if you want them to grow....LMB, HSB or something. In the one pond I stocked without predators, strangely the Tilapia did not grow out....they multiplied like crazy and when they died (see picture in Pond Boss magazine) they were all about 6 to 8 inches. In the ponds with predators, I caught many 2 pounders and one estimated at near 3 pounds. My unscientific conclusion was that the predators keep the numbers of small Tilapia fish down so that there is more food for those remaining.
