Of-course it "can" be done. But, you definitely need experience, extra effort, patience, and back up supplies. IMO he doesn't have enough jars there, but he might have more, i just didn't read the whole page. As said, youd need to supply extra food to supplement the Mandarins diet, and this can be achieved. Whether the person is willing to continue to do this for 3 years+? A nano CANNOT support a mandarin ON ITS OWN, but if you have one either feeding on frozen/prepared foods, or your wiling to supply its dietary needs for an extensive period (its whole life if need be), its feasible. Is it practical to have a non sustaining population of a fishes food source in your tank, no. Do we do this with other fish? Yes.