When can Sonar be used?

Sonar can be used in small ponds where the water is relatively contained. If there is heavy outflow, Sonar must be added more frequently or may not be good choice.

Can these products be used if fish are present?

In lakes, when used according to the label, are not toxic to fish. In ponds, the products used will generally hurt fish, but the rapid plant decay can lower oxygen in the water. Treating ½ the pond at a time will help keep the oxygen level remain safe for fish....