Wildco has developed the definitive low-cost apparatus for enumerating zooplankton micro-crustacea: the large Bogorov Chamber.
It is the perfect size to hold a large volume of sample - about 39 ml. The shape and configuration of the shallow, etched groove (1.27cm (1/2") deep and 0.95 cm (3/8") thick) help locate specific areas on the chamber. A compact 8.89 cm (3-1/2") by 11.43 cm (4-1/2") in size, it slips easily under a dissecting microscope. Straight sides mean you don't have to focus up and down. Rounded edges prevent specimens from catching.