i have kept lots of large cichlids at 70 degrees year round because that is the temp i keep my fish room,while they grow a little slower they all thrived. but i have been wondering about red devils as i have a house in florida and this year we seen we have red devils living in our 9 acre pond in our neighborhood,i have seen a few that are at least 10-12 inches and thick, at this size i am thinking they have to be in there for over a year but the neighbors say they never seen them before this year, no way to tell devil or midas. the water does get cold in the winter, we do not have a exact temp but we will check water temps in the pond this winter.i am guessing it gets low 60's maybe even 50's so wondering if they will make it through the winter or if they have been living there through the winters already.