When it comes to what are the right temperatures to maintain certain fish at is something that creates an element of debate wherever fish keepers meet. This seems to be even more evident when the subject it catfish, or in my particular case where Corydoras catfish are concerned. For this particular discussion I would like to deal with some of the Corydoras species that prefer the cooler end of the so-called tropical scale. When we use the term tropical we are usually talking of temperatures around 75? Fahrenheit. Here we are talking about a temperature range considerably lower, at 60º to 70º Fahrenheit (15.5º - 21º Celsius).