Lake Guard from Israel’s BlueGreen Water Technologies (reported here previously) has removed toxic algae from most of Israel’s 600 water reservoirs. BlueGreen recently purified the previously polluted 4.4-sq km Roodeplaat Dam Reservoir near Pretoria, South Africa. It took only a few days.
https://www.israel21c.org/meet-the-israeli-startup-making-water-drinkable-again/
https://www.youtube.com/watch?v=eT5DoDQS2CM (Amazing video)