SE Pond Mgt has promoted HSB as one tool to help manage crappie populations, so a healthy population there might assist. As CJ suggested, best to have a good predator base in place before you even think about adding crappies. You might also consider having a small number of really prime crappie structures in places you can fish easily-for ease of crappie removal if the population starts getting out of hand. I have two fairly large PVC "ball and stick" structures in a 3 acre pond that has crappies, but not a lot of other structure. With little jigs or minnows, I can remove a large number of crappies in a pretty short period because the crappies are always there.
Without a lot of management, many of us have found that "healthy fishery" and "crappies" don't go together too well. But there are exceptions, and if you're really dead set on them, go ahead.
