Best temperature for Fish Only Tank?

It has been sitting at 74 and goes to 78 with lights on at highest. Note} I never put fish in yet, so no fish are getting a temp swing back and forth.
I did not even plug the heater in was going to set it at 76 but thinking maybe 78 would be best. As Constant 78 would be better?????
I did not hook heater up as i wanted to see what natural temps would be out of curiosity. Our temps outside have gone from 78 to high 30's like 38-39 and is 41 today.
Tank still sitting at 74 Our weather is crazy here A/c one day lighting fireplace the next but my home stays pretty normal inside.

 

Same here in Alexandria la a/c and heat all in one day

 

Its better to have a more consistent temp but a swing of 1 or 2 degrees is fine. I would set the heater at 77. Most fish will be fine at that temperature but it does vary by species so be sure to research each fish BEFORE you purchase it.;-)

 

Agreed with Vinny. I also keep my reef tanks at 77°.

 

Thanks to both you and Vinny. 77 is doable easy!
I can keep the temp down from lights I have a fan. Just tried it without to see what it did and that was 78 with no fan.
And as i said a low of 74 no heater on so will set it at 77 and use the fan for lights on.
Was just worried 77-78 would be way hot

 

Unless you have (or will have) fish that come from colder waters, 77° will be just fine.