arcab.. unfortunately, (from my knowledge) there aren't any fishes that can scrape that stuff off the surface. I have a tough time getting that stuff off my 6g, but there are hardly any growing on my 10g. I think it depends on the balance of nutrients and stuff.
Your best bet is probably regular maintenance and not under/overfeed your plants.
Your best bet is probably regular maintenance and not under/overfeed your plants.