Right now I have them in the little divided tank that Wal-Mart has for them..... I can't see how they can be happy. I guess you could say I am a firm believer in the 1" per gallon rule. I am thinking of either putting one into my 2 gallon and getting another 2 gallon, or maybe getting the 5 gallon divided tank that I seen in the Drs Foster and Smith catalog. What would you do?