Compared to popular concrete biosand filter designs the Sandstorm biosand filter presented here claims to be lighter, cheaper, faster to make and requires no special tooling or molds. Tested in realistic field conditions in Ethiopia alongside popular concrete biosand filters Sandstorm delivers higher bacteriological removal efficiencies and larger water volumes. Though particularly relevant for implementation in a low-technology, small-scale enterprise model, the design also offers significant scale-up advantages for larger scale implementers due to the advantages of manufacturing speed and transportability. The innovative design follows a partnership between Tearfund UK and Desert Rose Consultancy in Ethiopia