wow so much excitement in this thread. I hope the op hasn't been thrown off by any of it. To the op. 
Although I don't think my input any more correct than anyone else' I will just say this. If you will be getting the fish at a small size it is safe to say you will need something like a 40 breeder for the first tank. Because of the extreme growth of RTC you will need to upgrade tanks every few months at first. If bought at 4" or less the 40 should last 2-4 months depending on it's individual growth. 40 gal breeder has a nice starting footprint for a small catfish. After that the next jump will need to be much larger. a 4' x 8' x 2-3' indoor pond would last a few years until you can arrange larger accommodations for it. Bigger jump in size of the tank is better than smaller so that the fish is handled and stressed less often. As for what size tank it should have in the long run???? These fish grow throughout their lives and some studies have suggested through analysis of the pectoral fin spine that large RTC may be as much as 40-60 years old at 80 lbs + in size. These fish would be over the 4' mark. Unless you end up with a genetic freak of a fish you will not see this size for many years. In the end it is the pet owner's responsibility to ensure the health of their animal and do what they feel is best. Every can argue all they want. No one can argue that yes the larger the provided habitat the better off the fish will be in the long run, but no one knows for sure exactly how the fish fares in smaller environments. For sure you will doom your fish if it is in less than 200 gals of water. Eventually the bioload will become too great and the fish will die for various reasons. 400 gals in the right footprint may hold this fish for life. How good of a life would that be??? not sure, but would be certainly much better in a 1000 gal tank for sure. If you look at vids of people that house them in multi thousand gallon enclosures they are not sedentary fish at all. They are actually quite active. I believe the size of the enclosure is key to the fish wanting to do more than just be lethargic and lay around. Of course it is in their nature to be nocturnal so for the majority of the day they will just lay around. But they do need space in order to be able to swim freely and at full speed when need be. In the future I hope to house one of these creatures in a tank of at least 4k gallons. I know from my personal experiences with them that they just act and swim much better in larger environments. They also tend to have less aggression towards other fish in larger tanks. We will never change your mind about getting one if that's what you want to do, but at least make sure that you provide the largest home for it you possibly can. PM me if need be. I am a master of ghetto fish keeping if that's what you have to do. Budget monster fish keepers can still do it, but it takes real dedication to build your own enclosures for a fraction of the costs of buying a ready made one. My planned mid tank for a rtc is currently 1200 gals. Of course it will be housed with other fish also. Hopefully I will get the green light from my landlord to build something in the range of 4-8k gals in the coming year or two. Good luck, and keep us posted
Although I don't think my input any more correct than anyone else' I will just say this. If you will be getting the fish at a small size it is safe to say you will need something like a 40 breeder for the first tank. Because of the extreme growth of RTC you will need to upgrade tanks every few months at first. If bought at 4" or less the 40 should last 2-4 months depending on it's individual growth. 40 gal breeder has a nice starting footprint for a small catfish. After that the next jump will need to be much larger. a 4' x 8' x 2-3' indoor pond would last a few years until you can arrange larger accommodations for it. Bigger jump in size of the tank is better than smaller so that the fish is handled and stressed less often. As for what size tank it should have in the long run???? These fish grow throughout their lives and some studies have suggested through analysis of the pectoral fin spine that large RTC may be as much as 40-60 years old at 80 lbs + in size. These fish would be over the 4' mark. Unless you end up with a genetic freak of a fish you will not see this size for many years. In the end it is the pet owner's responsibility to ensure the health of their animal and do what they feel is best. Every can argue all they want. No one can argue that yes the larger the provided habitat the better off the fish will be in the long run, but no one knows for sure exactly how the fish fares in smaller environments. For sure you will doom your fish if it is in less than 200 gals of water. Eventually the bioload will become too great and the fish will die for various reasons. 400 gals in the right footprint may hold this fish for life. How good of a life would that be??? not sure, but would be certainly much better in a 1000 gal tank for sure. If you look at vids of people that house them in multi thousand gallon enclosures they are not sedentary fish at all. They are actually quite active. I believe the size of the enclosure is key to the fish wanting to do more than just be lethargic and lay around. Of course it is in their nature to be nocturnal so for the majority of the day they will just lay around. But they do need space in order to be able to swim freely and at full speed when need be. In the future I hope to house one of these creatures in a tank of at least 4k gallons. I know from my personal experiences with them that they just act and swim much better in larger environments. They also tend to have less aggression towards other fish in larger tanks. We will never change your mind about getting one if that's what you want to do, but at least make sure that you provide the largest home for it you possibly can. PM me if need be. I am a master of ghetto fish keeping if that's what you have to do. Budget monster fish keepers can still do it, but it takes real dedication to build your own enclosures for a fraction of the costs of buying a ready made one. My planned mid tank for a rtc is currently 1200 gals. Of course it will be housed with other fish also. Hopefully I will get the green light from my landlord to build something in the range of 4-8k gals in the coming year or two. Good luck, and keep us posted
