NOVELTY - Microalgae are cultured by providing consortium of greater than or equal to 2 living species of microalgae, culturing consortium under illumination in controllable bioreactor under non-sterile aqueous culture conditions, and controlling culture conditions for affecting greater than or equal to 1 of the output e.g. (i) flocculation and/or settling of the consortium of microalgae and (ii) adhesion of microalgae to surfaces of the bioreactor in which culture conditions are controlled to promote (i) and/or to minimize (ii), without adversely affecting growth of the consortium of microalgae.    USE - Culturing of microalgae for biomass production (claimed).    ADVANTAGE - Parameters of the culturing method are controllable, such as promoting flocculation and/or settling of consortium of microalgae, and/or minimizing adhesion of microalgae to surfaces of the bioreactor or its components e.g. optical elements without adversely affecting growth of the consortium of microalgae which provide a robust system of culture, particularly less sensitivity to contaminants, pH variations, temperature variation, toxic gas, and reduction in luminosity and ability to adapt very quickly to stresses with regard to nutrients. The ability to control culture conditions facilitates and/or promotes harvesting of microalga. Costs of biomass production are reduced due to minimized agitation inside the bioreactor which promotes flocculation.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for controllable aqueous system for culture of microalgae comprising consortium of greater than or equal to 2 living species of microalgae in an aqueous culture solution, bioreactor forming an enclosure containing the aqueous culture solution, and controlling part for controlling culture conditions of the consortium in which the system operates under non-sterile culture conditions, and controlling part is parametrable for (i) optimizing flocculation and/or settling of the consortium of microalgae and (ii) minimizing adhesion of the microalgae to surfaces of the bioreactor, without adversely affecting growth of the consortium of microalgae.