Please refer to this page, which has a comprehensive introduction to aquaponics.
Right now, the Institute for Systems Biology is working on a crowdfunding campaign to help teachers like you obtain funding for building a classroom aquaponics system. We also recommend Donors Choose, a crowdfunding website specifically for education projects. Just create an account, follow the instructions and create a project to be funded. In this case, that would be your aquaponics system. If you are using Donors Choose, nearly all of the materials listed can be purchased from Donors Choose approved vendors. Click on the following for the Donors Choose 2×4 Materials List or the Donors Choose 4×4 Materials List.
Typically, aquaponics enthusiasts use Tilapia because they’re incredibly hardy, grow quickly, and can be harvested as a food source! Tilapia require slightly higher temperatures, so a small tank heater may be a nice addition to increase their metabolism and help them grow faster. If you’re not interested in harvesting your fish, goldfish and koi are great alternatives. People have also experimented with crayfish and freshwater shrimp.
One great part about aquaponics is there is very little maintenance required once your system becomes stable. In a stable aquaponics system, the only daily addition required is fish food.
Generally speaking, you want to have as little algal buildup as possible. Algae thrive in areas with a lot of light (from the sun or a bulb), but they also use much of the oxygen that would typically be available for your fish. To reduce the likelihood of growing algae, ensure all tubing and tanks in your system are black or opaque so they block as much light reaching the water as possible. This sometimes also means covering your fish tank as much as possible, while still leaving room for oxygen to enter.