I'm not sure about their actual min tank requirements, tho I know every once and a while I'll see the ones I have in my tank zooming around.... Mine at least love to exercise every now and again ( I see them more at night under the moonlight) and laying on leaves... Awesome to watch!! Mine started in a 55 now are in a 140... Sry I can't answer for sure.... But I'd think a bit bigger of a tank IMO.