My brother kept a L.M. Bass in a 65gal. Put it in there when it was 4''. If I remember correct, it grew to 15'' rather quickly. About 2.5 years. But it didn't weigh very much for his length. It was a glutten eater saying it was twice as bad as oscar he ever owned. He let it go saying that the width from front to back of the tank was too short for him to turn around in. Now, he's planning on doing it again with a 150gal tank.