I would like to throw a somewhat philosophic question out to the group. I have, over the last year or so, heard many references to having a heavily planted tank. Mostly, these references refered to the fact that with a heavily planted tank you can eliminate algae through competitive inhibition of phospates. I wondered what exactly the phrase "heavily planted" means. Does this condition exist when you can no longer see the top of the substrate? Is this a condition in which you have wall to wall plants? I have a 150g planted tank with persistent algae issues, though improving slowly, and wondered just how many plants are neccessary to reach this illusive state of shangrala.