Hi, it depends on his age, and where he is located in the house. Now when mine was young I had the same watt bulb only red Infrared Heat Glo bulb the same, it allowed me to see him at night, and gave him warmth if he needed it. Once he got older I put in a wattage of half.. I also make sure the temp outside his tank is not an extreme..you don't want humidity to be trapped in his tank as that will create respiratory problems. I keep our room around 70-72.....I have a well vented metal lid which also helps.. Now the aquarium store where I got him they do not have any night bulb... I keep it over his floating log,, now if he wants cooler, he goes over on his dock....so has a variety of spots of sit out of the water and sleep, digest his food etc...I still like the red light on.I can see him that way and my turtle is a 1 1/2 old and is doing great.. I hope this gives you some ideas.sincerely, Susan.
