Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Better to broadcast or spray Copper Sulfate?

CuSO4 is a contact killer meaning it has to be placed in contact with the algae to 'kill' it. If your algae is mainly along the shoreline no need to treat the whole pond volume - just the shoreline area. If most of the algae is on the surface use it as a spray. If it is mainly underwater dragging in a bag dispersing dissolved CuSO4 is effective. IMO do not use the entire calculated amount in the drag bag all at once. Too much copper dissolves all at once and too quickly and thus does not treat lots of shoreline. Divide calculated amount it into smaller lots and drag and dissolve each lot separately. Thus less copper is used or needed.

Every ounce that you apply will stay as a bound compound the pond sediment forever or until the sediment is removed. Chemically bound copper carbonate does not break down nor dissipate. Copper is a heavy metal and a stable element compound in the environment, thus it can accumulate in the pond bottom over time as it is repeatedly used .