I use the same method as Rob, my lights are on all day now and off all night. In summer i give my snakes no heat during the day and the lights are on all night. I have never lost a snake to anything temp related using this method, which cant be said about thermostats(including most of my eggs this year when the thermostat failed). The biggest wattage i use on my snakes is 40w spot bulbs, once you work out the bulbs you need, bobs your uncle. But in the end just use what works for you.