the invention relates to a method of cultivation of algae or cyanobacteria in the presence of a luminous material that converts light of a first wavelength to a second wavelength more suitable for use in photosynthesis by the algae or cyanobacteria , and apparatus for performing the method . in one embodiment the apparatus is of flexible plastic with fluorescent light concentrator or light guide and perforated pipe for bubbling carbon dioxide through the culture . the algae or cyanobacteria may be used to produce biofuels .