Abstract: A filter system for swimming pool cleaning machines comprising a filter tank cover secured to the pool cleaner and having a debris trap removably mounted on the rearward end thereof. The debris trap has an inlet end in communication with the water discharge conduit of the swimming pool cleaner. A flexible filter valve is positioned in the debris trap for normally closing the inlet end but which is opened by flow through the water discharge conduit. The discharge end of the debris trap comprises a plurality of spaced-apart ports having vertically disposed baffles positioned therebetween which prevent debris from sealing the openings. The transparent debris trap cover is removably mounted on the rearward end of the debris trap. A pair of filter tanks are removably mounted on the forward end of the filter tank cover and have filters positioned therein. The outlet end of the debris trap is in communication with the interiors of the filter tanks.