Copper sulfate is also available at the same locations. Yes, it will control the algae, but it is highly toxic to fish. The toxicity of copper is related to the hardness of the water, as the water becomes softer, the toxicity rises, so the area where the pond is located has bearing on the rate. Chealated copper compounds, Commercial algacides are relatively inexpensive and safe. These are available at local COOPs and farm supply stores.
Copper sulfate is also available at the same locations.