I have 20 acre lake that is having trouble producing size to all species that inhabit it. The bream and catfish are doing great with the catfish getting over 20 pounds in weight. My problem comes from the bass and crappie not getting any real size. Neither is really over populated, but the crappie won't get over 9 or 10 inches. I love crappie fishing so helping me correct them would be the most important thing to me. Also, the crappie species are black and not white if that makes a difference. Any suggestions will be greatly appreciated.