How long do you go without a bite before you decide you're in the wrong spot? I'm trying to figure this crappie fishing thing out. I spent 12 hours trolling in the past two days and I caught 2 keepers. Clearly I'm not in the right spots. Should I be looking go pack up my poles and move if I don't get bit in 15 minutes? 30 minutes? How long is "long enough" to prove the spot you're on just ain't gonna get it done?