Gordon's, Gallon, Ready Pour Formula, Pondmaster SeClear Algaecide & Water Quality Enhancer, Kills All Types of Algae Including Toxic Blue Green Algae, Controls Planktonic, Filamentous & Plant Like Types Of Algae, Helps Stop Algae Before It Starts By Reducing The Phosphorus Available To Fuel Growth, Fewer Applications & Lower Use Rates Are Necessary When Used Preventatively For Use in Still or Flowing Aquatic Sites Including Ponds, Lakes, Reservoirs & Potable Water Sources, Will Not Harm Fish Or Livestock When Used As Directed.