We have an aquaponices system right now. It produces very well. We have catfish, bass and crappie.
gettinaclue, that is exactly how we build our greenhouse because to actually buy a kit or ready made one is really expensive.
Mistakes were we started with kiddie pools just to test the waters. They did great but when we decided to expand, the pools were too flimsy and it wasn't easy to reach the plants on the far side of the pool.
Put your grow beds low! We initally put our beds about waist level and when the plants started growing, they really took off and things like corn and any vining plants just didn't have enough room to go up. With things low, you have the head room and you can put a trellis up for the vining plants.
Since we have two systems, one is low and the other is waist level for things like lettuce, peppers, chives, etc.
The clay balls are truly the way to go. Look on Craigslist to get them cheap. We cut plastic barrels in half to use as grow beds. To cut down the usage and cost of so many clay balls, we fill the bottom of the beds with washed gravel and then put the clay balls on top to plant in. The gravel helps to stabize the barrels and the clay balls are easy to plant in and harvest from.
It has been a few months since you posted on this thread, how are things going for you?