Abstract: A device for containing liquid media without complete mixing with each other comprises a container (3) with inlet (4, 5) and outlet (6, 7) ports, FIG. 1. Different media is supplied through inlet ports (4, 5) into predetermined areas (8, 9) inside container (3), FIG. 2. Some media mix with each other and form interface (10) between areas (8, 9). Mixed media is continuously removed from interface (10) through outlet ports (6, 7). This continuous media supply and removal of mixed media results in media distribution pattern where areas (8, 9) contain only supplied unmixed media.