Well first off if he is 4 feet then one mouse isnt nearly enough. I would suggest trying to get him to eat a F/T medium rat. Rats are way more healthier and you only have to feed one. We feed once a week. The temps need to be about 80 on the cool side and 90-95 on the hot side. Once you get the thermometers then you will know if that 60 watt is enough. Might try a 75 watt or even 100 watt but watch the temps!