Rapid growth in the bio-fuels industry recently has put tremendous pressure on food and animal feed supplies and agricultural land uses. In order for the bio-fuels industry to sustain and continue to grow, new non-food or non-feed biomass feedstock must be implemented and developed. The biomass production and oil content from algae is far superior to that of terrestrial plants such as soybean, corn etc. Because of the small size of algal cells, however, and comparably low dry biomass content of algal suspensions, the regular methods of separating are expensive and time consuming. On account of this, we studied such processes including algae cells in the culture separated with different kinds of polymers combined with Ferric Chloride. The entailed process of an adjustment of culture pH to between 8.50 and 9.50 followed by addition of different kinds of cationic polymers to a final concentration of 0.3 mg L^-1 combined Ferric Chloride with were investigated. This process was successfully employed to harvest cells of Chlamydomonas reinhardtii with efficiencies reached up to 85%. The process was high efficient and relatively cost neutral compared with concentration of algae by other chemical or physical methods. These experiments demonstrated that a commercial application of algae concentrated prepared by flocculation is feasible.