It's just that you mentionned cooler water, cooler water for me is in between 18-22°c, but yes most cories like the temperature you mentionned except panda cory (probably also others) like cooler water. To the other extreme there is the sterbai cory and adolfoi I think that likes warmer water like 78°f.I thought most cories like between 74-78 or am I wrong?