This paper reviews the various methods available for removing planktonic microalgae (microstraining, direct filtration, sedimentation, flotation, polishing using ozonation and granular activated carbon [O3+GAC], membrane filtration), and discusses their comparative effectiveness, optimisation and limitations. Also described are the treatments considered most effective in the removal of odorous and/or toxic metabolites. In each case French technology and its world‐wide applications are compared to those documented in the literature. The article concludes with recommendations on the most appropriate processes for treating eutrophic waters.