Filtration at moderate rates on upward-facing horizontal surfaces is accompanied by sedimentation. Kynch theorems developed for sedimentation in the noncompression range can be adapted to explaine the evolution of the cake surface and the filtrate volume with time. The different relationships obtained have been tested with filtration + sedimentation runs and filtration without sedimentation runs carried out with calcium carbonate suspensions at moderate pressure differences from 17 to 97 mmHg. The differences between the average specific resistance observed at the different runs can be satisfactorily explained by the fundamentals of the theory.