Ideas for the Growing System

Hi there! Today I would like to share some of the ideas involving the growing system I am going to set up in my school. First, the produce grown would be sold to the cafeteria. The money would be put back into the system to make improvements. Second, I plan on the system to be Aquaponic based, using fish waste as the source nutrients. The only problem is that I am not sure what to do with the fish once they die. Can they be harvested before they die, depending on the fish used? If you have any experience with this in a school or non-school environment, I would appreciate your ideas.