Heaters are always good to make sure the temperature stays consistent, especially over night. Is he active? Some fish adjust slowly, some right away. It just depends on the personality of the fish. Just really pay attention to how he's acting, and let us know if he is acting funny.
Kindness and respect should be shown to all animals, no matter if they are furry, scaly, big, or small. Be a hero to the animals and GO VEGAN!