ohhh, i have no idea! i keep my temp 78ish. im not sure on the exacts on him are but i know he is ideal for my set up. im sure there are other people that have them and can give you better advice than me. I do know that they eat more algea than my tangs. they will eat cheato, hallimeda, and anything else that is green in your tank and wipe it out quick. i think that they are hardy, i have heard that they dont get ick like most other fish.