It is well known that helical ribbon (HR) impellers exhibit poor bottom pumping properties. Three different HR impeller geometries, varying in their bottom design, are compared in terms of their mixing performance. Particular emphasis is given to the improvement of pumping capabilities. The selected bottom geometries were a standard bottom termination, an anchor‐type termination and a paddle‐type termination. The investigation was based on the use of 3D finite‐element simulation to assess the hydrodynamics and mixing performance using various distributive and dispersive criteria. Analysis of Poincaré maps showed that an HR with a paddle‐type termination operating in a down‐pumping mode offered the best performance. Copyright © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.