Before I actually explain this I would like to apologize for the picture quality, I happened to have my phone with me so I just used that.
This is just a showcase of one of my most recent projects, my hydroponic raft system. It's constructed out of plywood, 6 mil plastic, foam, and net pots. I also had a spare water pump lying around and decided that if I sacrificed one slot for a plant, I could put a smoothie bottle in it and had a pump shooting into it. This is supposedly a better way of aerating the water of the system, it also saved me from buying a new air pump. The system is rested on 4 cinder blocks and is 4 feet by 4 feet. The only thing that I would classify as a "con" for this build is that to fill the system halfway (in order to leave room to keep the raft from foating out) is approximately 27 gallons or around 100 liters, this leaves me at using around half of a whole bottle of the nutrient that I use, this is about 500 ml.
The story behind this is to do a comparison between hydroponics and aquaponics, I'm currently in the process of building an identical system and converting it into aquaponics. I plan to compare how much the initial cost of these systems are, how much the systems will yield (including tilapia), and how long until these contraptions make up for how much money I put into building them. As of now, the price for building this system is $56 (minus the price of the pump I had from earlier and tools).