Get him a new cage.
Just from looking at the few pictures you posted I can see multiple problems with your current setup. It would seem that you got some pretty poor advice.
Firstly, toss the red light. They are crap, shouldn't even be used around bearded dragons.
For your basking light you need a bright WHITE light, not a colored light. It can even be a normal household incandescent or halogen as long as it provides the temperatures you need. Which brings me to the next problem.
Your thermometer needs to get upgraded too. Those types of thermometers have been proven to be off by as much as 40 degrees. In addition, they can't give you the most important temperature of all, the basking SURFACE temperature. You need to get either a temp gun, or a digital thermometer with a probe end. Then you need to find what your basking SURFACE is, your hot side, and your cool side. And find the bulb that gives you your desired temperatures.
Yes you should lose the sand. Repticarpet is fine, so is tile, non-adhesive shelf liner, papertowels or even newspaper.
What
uvb bulb are you using? In your new tank you are going to want to mount it inside the tank so that the screen on top isn't obstructing the rays. You want your dragon to be able to get within 6-8 inches of the bulb at the basking spot.
Good luck, keep us updated.
-Brandon