i go down to the local stream, and use a dip net, and scoop out black nosed dace, they range from 1" long to 2" long, and are shaped just like guppies, i probably have 50-60 of them in my native tank right now, they seem to go down the drain, and into the sump, so i just scoop them out of the sump when its feeding time for the cichlids, i feed them live foods 1-2 times a week, and do a mix of pellots, sticks, bloodworms, and flakes on other days, my south american/central american's are still small in size, so when they get bigger ill need more feeder dace.
i think i have some creek chub fry and silverjaw minnow's also, they are just mixed in with the dace, there are also a couple white suckers, and johnny darters in the tank.
matthew