Think I can help you out here and make your next trip a little better. There's no better time to catch big crappie than February. Don't know is you tried drop shots with double minnow rigs but it is the best way to catch big crappie. Try using a 3/8 ounce drop shot weight. Before you tie on the weight, just slide two 1/0 hooks on the line then tie on the weight. Set the first hook above the weight about 15 inches and set with a double loop. Set the second hook about 12 inches above the first hook. Keep your loops small in the winter like an inch to limit the minnow to a lot of movement Watch your graph close. Crappie may be in a very small area of a brush pile. If the water is choppy, let the weight set on the bottom with a little slack in the line. This way the bait is not jumping up and down. Last never go fishing without crappie niblets on the hook with your minnow and get bigger minnows not small ones. Tail hooking the minnow is much better than nose hooking in the winter. Best of Luck!