What is your current water temperature a few feet below the surface? How big are your stockers? They look to be about 6" long?
If so, then most of them are probably sexually mature and should start spawning once they are happy and acclimated to your pond.
It is hard to measure accurately, but I believe some of our tilapia stocking pond owners think that it is the abundant spawn from the stockers that really cleans up the FA. I don't know how fast the tilapia fry will grow and become voracious eaters in your pond. But if they do thrive and grow quickly, then the stockers plus their descendants might be enough to get on top of the FA on Bill's 8-10 week timeline.
Even if your tilapia stocking does not eradicate the FA in your pond, then I suspect just breaking even at the current infestation would still be a much better result that some of the northern Oklahoma ponds that I have observed where the FA increases right on through August!
Were you able to pick your delivery date, or was the date somewhat fixed by your supplier? I would keep good records and try to get the tilapia into the pond as early as possible without putting them into cold enough water to induce excess mortality.
Good luck on your FA control project.
P.S. Do you have any plans to get tilapia OUT of the pond in the fall? As Bill says, the tilapia are just part of your "nutrient management" system. I believe if you remove a significant proportion of the tilapia each year, then you will also be removing some nutrients.
