A module enabling individual adaptation by the user to the respective task in the treatment of fluids using housings and connections of existing filtration devices without any modification is described. The module comprises one or more cells stacked one on top of the other, each of these having at least one opening, the opening of the cell or the similar openings of the cells together forming at least one channel for feeding or discharging the fluid to be treated. Each cell has two flat, porous components delimiting an inner space and designed for passage of the fluid therethrough, the inner space or spaces being connected to the channel. The inner space of the cell or cells contains at least partially a treatment material for the fluid. The method for manufacturing such a module makes provision for a treatment material to be introduced with a carrier fluid into the cells through the channel provided for feeding the fluid.