What is the ideal temp for my blue bullhead.I caught him in a soda cup about 6or7 yrs ago he is about 11in long I got him in a lake that freezes in the siearras.I've keept him in low to mid 70s his whole life but I want to do the best for him I can He has always looked great, eats like a horse,and has always been super healthy any input woult be great.