The C-Cube is an innovative ultra-filtration technology for the treatment and disinfection of drinking water. The filtration is done via micro-pores (average pore size 0.020 micron – sterile filtration) in hollow fibres with diameters of 0.3 – 0.5 mm. Due to the very small micro-pores only clean water can get inside the hollow fibre. Bacteria, viruses and solid particles in the raw water are kept outside Although the C-Cube operates in only one process step, it can replace conventional technology with flocculation – sedimentation – sand filtration and still reaches far better effluent values.