To those who reply to the OP: I have gone around and around with this guy in the catfish forum, everything from the nitrogen cycle, to feeding an RTC, to size requirements for his "ultimate build," yet he, I saw in another forum that he's already got another cat, a TSN, in this 55 gallon tank with all of these fish. I spent about three days answering his questions before I realized it was useless. Everyone, feel free to respond to him, but I have a news flash for you: He's not listening. If he was, he wouldn't have ANOTHER huge catfish in his tiny tank. And to you, OP, I'd ask that, for the fishes' sake, you stop spending your money buying fish and start putting some of that cash toward the tank or pond you'll need to build just to keep them allive. I have been watching you post in various forums, and in each post, you've added another potential monster to your woefully tiny aquarium with its HOB and sponge filter. Please, stop, research, and start to actually absorb the information that these people are spending so much of their precious time to give you.