So if I can get it to where next to nothing temp swing would that be best? And yes it happens slowly over night I have a heater on so it does not drop to fast
2 Degrees is really not that big a deal at all. My 55 has some major mood swings! about 75/76 with the lights off and about 81/82 with the lights on! Coral where doing just fine then! I have since added a fan and a heater to better control tempertures.
I have noticed that the fish look healthier! Much less ich problem! Corals still healthy, probally more happy though.
In tropical waters, at most reef depths the temperature changes not at all from day to night. And only a few degrees over the entire year. So the less swing you have the better, whether your starting point is warmer or cooler.