A flow chamber is provided through which is flowed a mixture of a fluid and a particulate. The flow chamber comprises at least one multi-phase water inlet through which multi-phase water enters the flow chamber, a water outlet through which water exits the flow chamber, a solids outlet through which particles having a density at or above a pre-defined threshold exit the flow chamber, and a low density outlet through which particles having a density below the pre-defined threshold exit the flow chamber. Also provided are one or more ultrasonic transducers and one or more reflectors corresponding to each transducer to acoustically filter the fluid and cause particles/fluid to be selectively diverted to one of the outlets. Related apparatus, systems, techniques and articles are also described.