The research question of this paper is: Which lessons for enabling a full scale recovery of phosphorus from waste water can be drawn from 1. an analysis of paradigmatic changes in scientific knowledge on P? In what way can these lessons inform scientists and (innovation) policy makers to stimulate a transition towards full scale P recovery from waste water? The paper draws upon a longitudinal case study of water management in the Netherlands and how it has dealt in science and policy with P, since approximately 1960 until now. It discusses and analyzes paradigm shifts in science and changes in the underlying organization of R&D on P. It ends with additional lessons on the most optimal organization of research and innovation infrastructures for the full scale recovery of P. 2. an analysis of the changes in the organization of R&D for phosphorus (P). Challenges relate to 1. the lack of a market for recovered phosphate in Europe, 2. the lack of experience of water managers in commercializing their findings and products 3. the lack of democratic legitimacy of regional water authorities 4. limitations put on the activities of water managers due to legislation and regulatory frameworks.