great list of fish you have pleco. Can you run down the sizes of them for us? As for the sizes I go off of an average for wild caught adults averaged with what most aquarium sites give. I give a range for the adult size instead of a maximum like most places give. Adult sizes vary greatly from fish to fish. There will be some RTCs that will never grow to more than 2 1/2-3ft., but most with proper housing should get to 4ft. + I have personally seen a 5ft rtc in a 300 gal aquarium. Granted he was not in very good condition and had been living in there for about 23 years according to the owner. His tankmate was another rtc of 4ft. They had sores from always being against the glass. The 5ft rtc looked to wiegh at least 80-100 lbs. He raised it from 4 inches from his account. Another thing to look at is the fact that rtc, and other large pims are wild caught for the aquarium trade, some are lab produced, but the vast majority are wild caught thus you should always go from the sizes for wild individuals. The old myth that a fish will only get as big as you let it only goes so far. The fish will get as big as it is genetically programed to get. If properly fed on a varied healthy diet a rtc should in theory be able to get more than 4ft. even if raised in a 4ft tank. Of course we all know it would bust threw the glass way before that. so to end the boredom I have caused I will say that it would be hard to say for certain how big a fish will get in captivity, but it is genetically programed to get a certain size and unless you stunt it, or kill it, it will attain that size, you just need to be one step ahead of it's growth. Also so that you know max size in aquariums is generally smaller cause most people don't know how to properly house a fish like this and end up accidentally killing it before adulthood. I have seen many accounts of people with rtc from 3-5ft. in captivity though if that helps any. Even in the wild it is rare to catch one more than 5ft. So basically it is the same.