to ATP!
That's a really good question, but I'm not sure you'll find the answer here. You might want to contact your local aquarium provider, because I'm certain they know more about how to prevent algae growth in an aquarium. As far as preventing algae in birdbaths, this works GREAT!
by the way, I just noticed where
@Trish answered a similar question for another member.
http://garden.org/thread/view_... In her reply, she says that copper is dangerous for fish, so you might NOT want to try this in your aquarium.