In my experience I wouldn't worry about it. My pond is 1/4 your size and I stocked 100 tilapia about 8" long. Survival rate was very high with exponential payback. My current water temp is 82 this morning. The tilapia have been spawning for about six weeks when the temp would stay about 72.
Seeing them swim around is easy. Seeing them on beds is easy. Feeding them is easy. Catching them is hard.
