My little guy is in a 20 gallon tall tank and I use a 100 wat red bulb and leave it on all the time. The red light isn't offensive to their eyes like a white one would be . He still gets his 12 hour cycle from the windows and the light in the living room. I don't use a heat pad for him and my temps stay perfect. 97 on the hot side and 85 on the cool. There's controversy on heat pads if u don't have them on a thermostat. They could potentially cook ur snake and no one wants that!

If ur switching from bulb to pad I would make sure the pad is all the way heated up before u turn the bulb off. If not the temps could fluctuate a lot before it heats all the way up which could also cause ur little guy to stress. Just have to find out what works best with u and ur little noodle.