This is not new, anyone heard of ORA?? They USED to offer captive bred mandarins but they stopped because people who purchased their captive bred mandarins expected them to be easier to feed and when they were not those people got really upset about the high price they paid for a captive bred dead fish. Being "captive bred" does not change an animals basic needs. Some people have luck with sponge set ups that they seed pods into if they don't have a large enough tank to have enough live rock to sustain a large pod population. In this case, we are talking about 20 gal nano, IMO this is just not a proper home for a mandarin. Maybe there is someone on here who has kept one, however these guys have potential to live 15 years, so if they say they have had one in a nano for 3 months and it is doing great, take that into consideration. These are beautiful fish, it breaks my heart to see them starving in pet stores. If you decide to try it, just be prepared. Good luck.