Crappie seem to feed more in low light conditions early morning before sun gets up high or as sun starts going down. At night the use of lights works well, too. This year I plan on buying a couple of the green 18 inch fishing lights from Bass Pro about $24.00 each. Several things to remember the light is the structure you are fishing, but pick an area where crappie can be found. It will take 45 to 60 minutes to set up the food chain. The plankton will arrive first, then the bait fish, next the crappie, and the catfish. Do not fish to deep crappie come up to feed they are looking up not down. If you start catching more catfish than crappie shallow up.
Hope this will help.