Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
There can be a pretty complete biological habitat going on in an aquarium. It sure is not as simple as a glass box with water!
Yes, fish food can be the ammonia source to finish out the cycle. Feed about twice as much as you might ever think about feeding fish or shrimp. You could also add a shrimp (kitchen/grocery store) or prawn. As these rot they supply ammonia. (and smell bad).