I do by the way have a couple Nerite snails that aren't doing anything at all with the dead leaves, but apparently Apple snails are rare in being able to digest cellulose.
And is there anything that would eat hair algae in my planted bowls? My Amano shrimp aren't touching the stuff... Thai Micro Crabs maybe?
Incidentally, is that an error in the documentary where it suggests that by eating the decaying vegetation the Apple snails supposedly save the waterways from low oxygenation? Wouldn't the snails use up just as much oxygen while reducing the decaying plant matter as bacteria itself would use up to accomplish the same thing?