What will the fish eat?
Where will the food source come from?
How much will the water need to be circulated?
How will feces and urea be handled?
What is their habitat going to be like in the tank?
Lastly, how is all of this going to fit inside and work together within the tank?
I found an article by Backyard Aquaponics called the "The IBC of Aquaponics". It is chocked full of useful information, just about anything you could ever want to know about aquaponics. I have not read it, but from what I can tell, I think it would be helpful.
I like channels (catfish in general) over other species...even my trout. You may consider brown bullhead instead as they will breed in larger takes. It all depends on oxygenation/filtration of the water, nitrate levels, etc. Look at advanced fresh water vivarium and aquarium sights as well. These are good sources too.
My real concern is that you're building a system large enough that you're going to be selling produce, but my impression is that you haven't taken a commercial aquaponics class. There's a steep learning curve and I'd hate to see you end up in a bad spot. 90% of the challenge you'll face is marketing.
Andrew Watkins wrote:I had planed to start my system with Taliapi and had purchased two IBC's for fish tanks. I have since decided to use channel cat fish, and because they tend to stay on the bottom I am wanting to figure out how many 4 - 6" catfish I should start with per tank. The tanks are 45" X 36" wide. Does any one have some experience with this, I am in need of advise. Thanks!
Okay, the system I just built in Holland had a fast growing catfish that was half African and half Asian. If we did not have a minimum of 75 fish per full IBC of water they would turn on each other and start killing each other. They are a schooling fish that is quite aggressive. Somehow having more makes them more comfortable and they calm down. For schooling fish we generally have one per gallon or less in our systems. But we have fish in all sizes so the overall system does not have (in your case) 500 fish all at plate size. So you want to space out your fish purchases and maybe put in separators to keep the little ones safe. I am sure you know that harvesting more than a fifth of the system at any given time can cause it to crash, so separators might aid in this.
That being said, I don't think you can stock the Channel at the same rates as the Asian or African, from what I've read you can stock more with more feeding and maybe you don't even need to separate them as they have some sort of Hierarchy system.