It's funny how this conversation went. To start, yes I have taken some commercial aquaponic training, and thank you for you concern I truly appreciate that. My original question, I apologize for framing it so poorly, has to do with my decision to change to channel catfish. I am starting out with two IBC containers as fish tanks (I will be building a large tank in phase II) and they would work just fine for Tilapia but I have decided to go with channel catfish instead. I realize that they are bottom dwelers and because IBC tanks are somewhat tall and narrow, I was hoping to get some input from someone who has experience with channel catfish in a tank. I would like to determine if I will be loosing a considerable amout of fish volume due to them being bottom dewllers. Thanks again for you time and words of wisdom.