In recent years, microalgae biomass has been recognized as a useful source for a wide range of applications, such as biofuel production, CO2 fixation, food, and cosmetics. As the demand of microalgae increases, improvements in biomass production and harvesting techniques are required. For example, dewatering processes increase the total production cost, especially when performed in large footprint systems, such as open ponds. The aim of this study is to investigate and optimize membrane filtration as a compact solution for microalgae harvesting with the target to reach the goal of zero liquid discharge: the permeate extracted during the process is reused entirely or partly as a new medium for algae regrowth.