Hemacytometers and cell counting chambers are used for Howard mold counting, fecal egg counts in animal health, counting low leukocyte concentrations in white blood cells with a Nageotte Chamber, counting plankters with a Palmer Nanoplankton counting chamber, bacteria and sperm counting with a Petroff-Hausser Counter, cerebro-spinal fluid cell counts with a Fuchs-Rosenthal counting chamber, and drinking water analysis with a Sedgwick-Rafter Cell Counter.