BP in hide all the time?

[Adam Chandler]

" a hiding BP is a happy BP"

-jamie

Very true. In fact, if you see your BP out of his hide most of the time that means they are not happy and looking for a way to escape and move on to a more comfortable area.

should i only use an undertank heater or use that along with the heat lamp? and should i put the heater under the hide he is always in?

I personally do not recommend the use of a heat lamp. BP's do not bask, they only require surface heat. Most of what a heat lamp does is just dry out your enclosure and make it hard to maintain at least 50% humidity.
All your BP needs for heat is a regulated UTH, and yes it should be under your BP's warm hide. You want the surface under his warm hide to be 88-93 degrees. The best way of accomplishing this is to hook up your UTH to a thermometer such as a Hydrofarm http://www.amazon.com/Hydrofarm-MTPR...2641610&sr=8-2 or any thermostat RBI sells http://www.reptilebasics.com/thermostats.
And If you don't already have one I would also recommend a IR thermometer (such as www.tempgun.com) to keep track of the surface temperatures of your BP's enclosures.