Did the algae come back yet? In our pond the rain just beats the algae into the top of the water column. After a few days to a week, the algae reorganized and forms on the surface again. Hopefully this is not your case, but be prepared.
We use Crystal Plex sprayed with a tank sprayer and had really good results killing the algae on our lake. It has copper sulfate in it that really zaps the stuff.
