The Chinese economy has experienced unprecedented growth by over 10% per year over recent decades. While tower-blocks arose at the horizon, demand for food, energy and luxury products increased. A side effect of this growth is the release of waste to the environment. Toxic algae grow well if these waste fluxes exceed a certain level. The question for the Taihu lake is: what exactly is too much? With a mathematical ecosystem model called PCLake, Annette Janssen estimated the amount of waste at which toxic algae start to dominate. The model results indicate that the waste should be reduced to 90% to meet the highest standards.