The Pond Guy Defoam is for use in all size ponds. This natural defoamer gets rid of unsightly foam in seconds leaving water naturally beautiful. Note: Persistent foaming indicates a high level of undissolved organics. To help reduce foaming and increase water quality a partial water change may be needed. It is recommended to partially drain and refill the pond at least twice a year treating with an initial dose of the pond foam remover each time. You can also try the The Pond Guy DefensePAC. The DefensePAC is a comprehensive pond care system that helps to remove excess nutrients in the pond.