PlanetCatfish.com

For a school of 4-6 of these UDC, a good sized tank if they are the only inhabitants?

(well, aside from one banjo cat who refuses to come out and be moved to the banjo community!)

6 nigriventris could have room to move in a 60-80 cm tank, but if you keep them without dithers you won't see them, period; not even when feeding......

I'd say, go for the 80, but add a shoal of lively barbs or so.