greenest possible aquarium?

I was given a 50-ish gallon aquarium and stand, and would like to get it up and running in the most environmentally friendly way possible. I have purchased some gravel already. Help! And thanks!

Comments

[RelaxedSoup]

You could make an aquaponics system with it.

http://www.instructables.com/id/Organic_Hydroponics_Aquaponics/

You could also try building a solar power supply for the pump as well, using the same general concept as seen here. Then it'd be totally off the grid!