Powerheads
Powerheads, while relatively inexpensive, produce only laminar currents. If you choose to implement a powerhead, do not aim water flow directly at invertebrates - the flow may be too intense and organisms may suffer damage. You can, however, direct flow to a specific area to reduce detritus buildup. Depending on your aquarium setup, you can create multi-directional flow with a powerhead by adding PVC pipe and fittings to the outflow.