I am a student teacher from PSU and I am doing a hydroponics unit this spring. The school has a hydroponics system in the greenhouse but I was hoping to maybe have the students create their own for a class project and incorporate some ag. mechanics into a lesson. But I am limited in how much I can spend and I have been searching the internet to see what I can find cheap and what kind of system would be cheapest. I am just looking for ideas if anyone has done something similar. I would like to keep it to around $10 per student if possible. I have 12 students in the class.