Holidays and Traditions How to apply Sonar one? Does sonar herbicide kill fish? Aquatic Weed Control that doesn't harm fish Due to its specific mode of action, Sonar does not affect wildlife, fish, or humans when used at the recommended doses. What is the active ingredient in Sonar? fluridone Related Posts:There are pros and cons of fish farming, and there are drawbacks.Fertilizing a lawn with chicken safety in mind.How much does Reggie cost?Why do we need Sonar?