I heat my water but only because I have it being made outside and even in florida we get some cold nights. lol I aim for a few degrees either way, as MrX said, it usually doesnt change the tanks temp much if at all. Especially since you are doing small changes I doubt you will see any change at all.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.