To adapt to new needs in the market, my supervisor and I outlined the following design goals: 

• Compactness (~50% reduction in volume, ~25% reduction in column height) for indoor placement

• Integrated post-filtration storage to reduce contamination risk from separate improperly cleaned storage containers

• Aspirational design to improve user acceptance.

To evaluate how changing parameters interact and affect filtration, I conducted a literature review on BioSand Filter (BSF) research. Based on my findings, I identified five key parameters that significantly influence water quality and decided to monitor them closely.

To avoid starting from scratch, I chose to work within the size constraints of a 2019 prototype developed by a former Clear Cambodia employee. One critical parameter missing from the original design was the requirement for equal charge and pore volume—an industry standard and a strict constraint for my design.

I modelled various factors, including volumes, water age, peak flow rates, residence times, and predicted log reductions based on trends in the literature. I evaluated different options by considering flow loading rates, the number of charges required for the user (burden), water age in the storage container, the potential for increasing the biolayer surface area, etc.

I worked closely with a manufacturer in Phnom Penh to create a physical prototype (without the surrounding water reservoir), in order to test its filtration capabilities.