I've offerred to rehome an upside down catfish (in a 65L community tank for a month or so, then into a 85L / 3 ft tank) and I've done enough basic research to know that he should be alright in my tank. I was just wondering if theres anything worth noting about him, any special care needs or requirements?

i have an upside down catfish,which to be honest i dont see very often, he/she likes to hide behind rocks and then when the lights go off at night you see him come out, he likes the bogwood and seems to like to graze on that i also have another one that is a bit larger and he hides in the an ornamental plane allday but it is fummy when they swim around upside down everywhere

Which species is it? All Synodontis are called upside-down catfish, though S. nigriventris is the most common species sold under that name. There is also an Asian upside-down catfish that's an altogether tougher customer than most Synodontis. S. nigriventris is a social, schooling fish, happier kept in groups. Most of the larger species are less tolerant of their own kind, and do well enough as singles.