Flocculation tanks are used to mix polymer and sludge prior to sludge thickening or dewatering. Flocculation tanks are supplied with variable speed agitators, but the speed is very rarely changed during normal operation. Floc tanks generally have an open top, which allows operators to easily visually observe floc conditions. In applications where odors or harmful gases can be present, floc tanks are supplied with a cover. FKC manufactures floc tanks in numerous sizes to meet the individual needs of each application.