Pond Boss Forums INTRO Questions & Observations diquat

Often an underwater application works well especially if bottom aeration is present to disperse the chemical. What is the weed species? Does it have floating leaves or is it producing a surface flower/seed head yet? If most of the leaves and stems are underwater then spraying most of the chemical underwater among the weeds is a good application. Are the weeds completely covering the pond area or is there open water in the middle area? Sometimes a thermal stratificaiton will limit the depth penetration or distribution of the herbicide.