Abstract: A sludge filter is disclosed of the type having an open-topped tank adapted to receive a quantity of sludge, and one or more filter panels vertically disposed within the tank. A hose connection extends between each panel interior and the tank exterior to draw filtrate from the panel interiors to sewer or other discharge lines. The panels comprise hollow, flexible, bi-walled, slick-sided, artificial cloth filter bags carried over open frameworks of appropriate size. The frameworks each include a top frame member having a length sufficient to extend over the tank sides and thus support the depending framework and bag within the tank.