We built a system using concrete at an orphanage in the mountains of Honduras. The system has 3 fish tanks and 3 - 50' raceways (Grow beds).
Why concrete?
Our "prime directive" when working in developing countries is "If they can't reproduce it, we don't introduce it". The system was designed to use concrete because that's what was available and there were local workers to help. The local culture was very familiar with building cisterns and that's what they did!
Fresh Fish!
Thanks to the new aquaponics system, the boys at House of Mercy are changing their diet and have recovered from malnutrition!
They are able to go to school and one has gone to college!