Abstract: A sludge collector includes a collection box disposed within a sludge holding tank containing a liquid and the sludge or other materials to be collected. A floating weir is positioned at the inlet of the box to control the depth of a stream of materials flowing into the box. The weir operates to automatically match the flow rate into the box to that out of the box without employing complex sensing or actuating mechanisms while at the same time assuring that adequate turbulence is created in the box to mix sludge with the liquid prior to removal. The weir is also designed so as to reliably handle sticky materials. Preferably, the pump is specially designed to handle sticky materials without clogging, and baffles are located upstream of the collector to facilitate prompt sludge collection.