Filtration is the most competitive method compared to other harvesting tech­niques. It is most appropriately used for relatively large sized (>70 pm) algae such as filamentous species or agglomerates. Diatomaceous earth or cellulose can be used to increase filtration efficiency (Brennan and Owende, 2010). However, con­ventional filtration operated under pressure or suction is not suitable for smaller sized algae such as Chlorella, Dunaliella, and Scenedesmus. Membrane micro­filtration and ultrafiltration are alternative filtration methods. The disadvantage of these processes is their high cost due to the frequent replacement of membranes and pumping costs (Pittman et al., 2011). There are many different types of filtra­tion processes, such as dead-end filtration, microfiltration, ultrafiltration, pressure filtration, vacuum filtration, and tangential flow filtration (TFF). Mohn (1980) stud­ied different pressure and vacuum filtration units for maximum dewatering of algae and warned against the use of these filters for harvesting Coelastrum probosci — deum as he did not find it appropriate. However, he demonstrated that filtration processes can achieve a concentration factor of 245 times the original concentra­tion for C. proboscideum to produce a slurry of 27% solids. Recent studies reveal that TFF and pressure filtration can be considered energy-efficient dewatering pro­cesses as they consume minimal amounts of energy considering the output and initial amounts of feedstock (Danquah et al., 2009). Simple filters can be used with centrifugation to achieve better results. Mohn (1980) and Danquah et al. (2009) have presented data on concentration factors and energy consumption of all filtra­tion units. Large-scale recovery of microalgae using this technique is not recom­mended due to continuous fouling and the subsequent need to replace membranes. Few researchers have tried polymer membrane for continuous recovery. However, the performance of these membranes depends on several factors, such as hydro­dynamic condition, concentration, and properties of microalgae. Although this method appears as an attractive dewatering method, the significant operating cost requirements cannot be overlooked.