I was keeping my temps in the mid 70's.My T's weren't real active and not eating very much.I cranked the temps a few degrees.I now keep the temps in the high 70's-low 80's.What a difference a few degrees makes.My Ts are way more active and eating like crazy.I'd say no less than 78-80 dgrs for happier more active T's.I also find the slightly higher temps help maintain a better humidity level....peace...