Abstract: A continuous self-cleaning centrifuge assembly has a feed inlet (23) to the centrifuge (10) for unclarified liquid, an outlet (29) for clarified liquid, and means (42,39,38) to discharge solids out of a solids holding space (26) in the centrifuge in response to a monitored turbidity parameter of liquid in a detection line (35) in communication with the centrifuge separately from said outlet (29) so that said turbidity is affected by the degree of build up of solids in the centrifuge. In another aspect, a continuous self-cleaning centrifuge assembly has a feed inlet (123) to the centrifuge (110) for unclarified liquid, an outlet (129) for clarified liquid, and means (143,139,138) to discharge solids out of a solids holding space (126) in the centrifuge in response to a monitored turbidity parameter of liquid in an outflow line (128) connected to said outlet (129), wherein said turbidity parameter is the rate of rate of turbidity increase, or second derivative, of the monitored turbidity.