It could work, temporarily. While initially stocked crappie can survive and grow, with adequate food, the situation must change.
It's not a matter of "if" as much as "when".
With overcrowded bass, stocking crappie only adds more predator mouths to feed, and you likely are adding a different problem on top of the problem of too many bass.
Want to manage predator fish?
Become an expert at managing what they eat. Forage fish.
