when i started with fish i was warned about algae problems and snails. (snails aren't and issue and won't ever be). well, i have an unplanted tank with mollies and cory cats right now, and some betta tanks. non have algae. what causes some tanks to develop major algae problems? does it have to do with lighting or amount of direct sunlight on a tank? do plants contribute to or help eliminate algae? not that i really want algae, just curious..................