Look at my Uruguay thread in my sells forum, got some pcitures there. Centurion is along the Brazilian border with Uruguay, When we were there in late Novemner night temps were still getting into the 40's. Felipe calls the G. labiatus from tha region Blue Yerlito. Ph is 7.2, with fairly soft water, No heater needed, but they can take higher themps for part of the year. I don't really think you need a real cold period as they are being bred in Florida on fish farms in ponds near Miami. Ken