Jackson - though I sell copper sulfate, I'm not a big fan of its use by any means - particularly in ponds that support fish. In general, the negatives associated with copper sulfate outweigh its perceived economy. Chelated coppers (CUTRINE, etc), if appropriate, are much preferred over the antiquated copper sulfate formulations.
I'd suggest that you run a search for the term "algae" and/or "filamentous" to find the numerous posts that deal with that subject.
Basically, killing filamentous algae is a quick fix for a symptom of one or more underlying problems. Sometimes it may be warranted. But, don't engage the effort thinking it will be a one-time affair if the actual problem is left unchanged.
