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 (50) is of flexible plastic with fluorescent light concentrator or light guide (76) and perforated pipe (56) for bubbling carbon dioxide through the culture. The algae or cyanobacteria may be used to produce biofuels.
