My advice, ditch the backlight, and get an infrared heat lamp. backlight bulbs are less efficient and won't heat the cage as much as an infrared heat bulb of the same wattage will.

I would suggest this bulb: (Get the 75 watt version)

http://www.petsmart.com/product/inde...AvailInUS%2FNo

Temperatures are more important then humidity, so focus on getting the air in the cage around 80 F and once the thermostat comes in use the heat pad to create a 90 degree hot side. Heat pads don't do anything for the air temperature in the cage, so all it will do is create a 90 degree hot spot your BP can sit on to warm up.

What thermostat do you have conning?

You should be able to use your heat pad again once your thermostat comes in.