77-78 when I had the chiller hooked up ..... don't have it running right now and temp seems to fluctuate from 76 at night with a/c lowered to about 81 during the day with halides on and a/c not cranking as much. Planned on putting the chiller back on line but haven't noticed any ill effects from the temperature swing so far so I'm just monitoring for now - nice to have one less piece of equipment running.
Since warm weather is here, and I have most of my system outside. I just turned the system temp down to 77.5 to give me a couple more degrees of comfort.