Cecil- no I don't have that covered haha. Can you explain a little bit about biofiltration please?
Too much to cover here. Let's just say if you put fish in a tank with no water changes, even with plenty of oxygen, eventually they will poison themselves by the ammonia they give off in metabolism. You need a bacterial culture growing on some kind of sufarce to oxidize that to nitrites and then nitrates, which are benign to most warm water species of fish. Aquarium biofilters do it all the time.
I would suggest the book Small Scale Aquaculture by Steve VanGorder. Less than 20 dollars on Amazon. However if you are really interested, I would not build the RBC in the book as it's about $500.00 in materials. I would go with a moving bed filter in a 55 gallon drum which consists of an air source in the bottom (diffuser) and plastic media for the bacteria to grow on. Can direct you on that if you're interested. Cost would be less than a fifth of the RBC.
