Yes it's 18 inches wideI think 75g have a width of 18in if right then should be ok.
Two will be good. As long as ur catfish isn't smaller than their mouths it should be fine.
Okay thanks for clearing things upPalmas and delhezis will get in the 12-14 in range given space and time. 75g should be fine.
Yes you'll need a cover for the top due to always launching themselves but a weighted glass top or cut acrylic can do this. Some use eggcrates as another cheaper option.
How big do pollis, retros, and mokes get? I keep seeing different info as well.Another option would be palmas palmas, palmas polli, retopinnis, and mokelemembe depending on availability.
Also whattlindsey has mentioned. But can't add all of them lol.