Disclosed are embodiments of apparatus for sorting particles in a fluid stream by size. In one embodiment of an apparatus for sorting such particles, a housing is provided, which defines a channel for a fluid stream containing particles. A suction channel is also provided, which terminates at a suction port. The suction port is positioned adjacent to the fluid stream. The suction channel may be configured to create a low pressure region and thereby redirect particles in the first fluid stream such that they may be sorted by size.