theyre rainbow trout. the temp is between 58-62 theyre in an unheated tank in my garage so it fluctuates. a powerhead isnt required but they do enjoy the current. they were extremely easy to get on pellets. a day or two after acclimation and they were eating like champs. theyre also eating crawlers, frozen shrimp, cut fillets, and mealworms, pretty much anything meaty. they will take down feeders as well. i currently have a 7" and 11" trout. theyre extremely active and far from shy. one word of caution though they can be very territorial fish, it depends from fish to fish.