Aquaponics System Blueprints!

Hi and welcome to my blog. Since this is my third post, I will fill you in on some information about this project. I am designing and building a  hydroponic system for my school. The food grown cannot be used in the school cafeteria. I have decided to donate the majority of the produce grown.

I have developed a design for the system, and need some feedback. I am looking for ways which I can improve the way the system works, if the design is feasible, and if it is not, what can I change to make it work. 3 inch pvc piping would be used (the sheet says 4 in.)  and I would cut 2 inch holes into the pipe to place the netted cups into. The water would be pumped from the reservoir to the upmost pipe on the right hand side. The water would be pulled down the pipes by gravity and empty into the reservoir on the left hand side of the system.

I would appreciate any feedback. Thanks!