1 fishing bobber (floating thing)
some fishing line
lead fishing weight
some snaps (they're in the fishing tackle section along with everything else)
i dont have pictures right now. but tie some line to the bobber. make sure the line is long enough so the lead weight will hang just above the substrate. tie the weight to the bottom. then tie a couple of snaps at different heights.
when you want to feed you thread the snap in to the food, then let it go.