Pond Boss Forums MANAGING AN EXISTING POND Fertilization Too late to fertilize?

Cutrine Plus is not a herbicide, it's an algaecide.

Are you 100% sure on the ID of the plant?

https://aquaplant.tamu.edu/plant-identification/alphabetical-index/hydrilla/

If you are 100% sure on the ID:

If I was treating the pond for a customer I would use a mixture of Cutrine Plus and Galleon, making sure I applied it according to the label. READ AND FOLLOW THE LABEL DIRECTIONS Don't forget to check the alkalinity of the pond to adjust the amount of Cutrine Plus and don't forget to use an approves surfactant with the Galleon. I would treat it by subsurface injection.