The amount of fine sediment in a stream affects how much sediment is carried by the water. In lab experiments, researchers found that having more fine sediment near the stream's source compared to further upstream changes how sediment levels change with flow. Different sizes of sediment particles also play a role. The mix of sediment sources can cause sediment levels to rise or fall in the streambed. Sediment levels at the start of the stream don't match what's seen further downstream. Mixing different sediments can even reverse the usual pattern of sediment levels changing with flow. The balance between sediment sources affects how much sediment builds up or washes away in the stream, affecting both sediment levels and water flow.