Sir Intimidator is correct. Both bluegills and crappie are PROLIFIC breeders, crappie often FAR more so. Unless you have a BIG pond OR stock it heavily with baitfish and establish a predator heavy environment (difficult to do ) the crappies will simply rapidly out breed everything else in the pond and overwhelm it, leaving you with a zillion 3-5" crappies after eating most of the predator`s fry and juveniles. Am not saying that they aren`t cannibals (luckily, they ARE !) but for every 9+" crappie in your pond there will be 50 stunted 1s....not an "ideal" fishery !