ecology

Can I raise Gammarus or some other live food off the back of a ten gallon in a 3 gallon container? They would be food for Guppies, Least Killifish, and maybe a Betta.

Hey, this is my first post so I am not sure how everything runs.   In my biology class we were given the assignment to basically make a self sustaining ecosystem in a sealed of container. It is a nightmare. In order to keep everything running we obviously need plants to convert co2 to oxygen. To...