I agree wth Flora, but also, you only have a 46 gallon tank, but you have a ton of fish in there, all generating waste which can contribute ammonia, and the discus are, I assume, being heavily fed, so the excess food also contributes ammonia.

You need to clean out the algae that is now in the tank, either kill it or remove it. It will continue to thrive unless you get rid of it. Then, with heavy planting, good fertilizing, not too much light, and not too many heavy eating fish, regular maintenance on the tank, you can keep the algae from coming back.