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- Mostly BIG fish and some coral. ~80g Nuvo- My coral tank with "happy fish"~ 90g- FOWLR Not the not happy type of fish~ 125g- Freshwater Malawi Cichlids ~10g- Nuvo- The refugees from the Ich of '18