If you’re marking schools of whatever down in the water column over deep water but not on the bottom, tie on a three way with a foot ling dropper for a 1/4-3/8 weight and a 5 foot leader for a floating Rapala about a size seven and run that thru the school. Summer crappies will chase BIG baits when they’re following water temps or a thermocline. Take off the front hook on the Raps.
If you use a bit more weight you can either speed up some or you can use a larger Rap. Yozuri makes a few nice minnow sticks that are smaller and effective.
I trolled run of rip-rap in a Mississippi backwaters for years with Raps on three ways looking for walleyes and caught as many crappies as walleyes….using a size 13 Rap. These were always very large crappies. If I am in a boat during the summer heat and the water temps have gone way up and schooled crappies won’t pay any attention to a jig/plastic, the three way with a mid sized floating stick generally gets the nod.
I seem to do much better with smaller cranks that have a chubbier profile when the water is still half cool to cold. Sticks are chasing baits and even semi-lethargic crappies will chase to a degree if the profile is more minnow-like. One just has to make a few passes at differing speeds to figure out what speed will elicit hits.