Okay, this has gotten out of hand.
The bottom line is this: the OP knows his tank is too small, and got the fish anyways. That's fine, you can always buy a bigger tank. However, his idea of a big enough tank for the fish to live the rest of its days is a 250, and that isn't enough by a long shot. So, my recommendation to the OP is the same I made in my very first post, which was not at all intended to be snarky or condescending, but if it came across that way, I am sorry. But I will not simply pat the OP on the back and congratulate him on his purchase when I believe something is amiss. After all, we're all here for the fish and their well being.
So, OP, consider getting a much bigger tank (or a cattle trough, or a kiddie pool, anything that the catfish can live in for life and that won't suck your wallet dry). I personally like the troughs at Gempler's, although the biggest one there is only 400 gallons. It's got a 6.5 foot diameter, which isn't really enough for the RTCxTSN. If that isn't an option, sell to someone here on MFK whom you know will be able to take good care of that fish.
Glück.