Have you got any fish that enjoy soft acidic water? I don't know for certain, and I'm not sure anyone does (not a lot of research done on this yet afaik) but I would think it would be good for any fish that like the PH on the lower end of the scale. That's why people use indian almonds leaves with bettas. Well that and because they can be found in a betta's natural habitat I believe, so it's kind of a way to replicate their habitat.
Hope this helps!