Crystal-Plex is the product to which I refered earlier (~TSC). Not as good as CUTRINE, in my opinion.
Stay away from copper sulfate. It does work, if only temporarily, as an algaecide. But, the short duration of algaecidal activity and the fate of the excess copper in your pond are two big strikes against it. Stick with a chelated copper algaecide - if one is used at all.
I would come closer to suggesting a microbial treatment for your pond, to help reduce the availability of nutrients that are fueling the excessive algae (instead of simply recycling the nutrients with repeated copper treatments). However, regardless of the method used to reduce the algae population, you'll need to be ever mindful of your pond's DO level.
