Bearded Dragon not eating/not active

Question
I have a bearded dragon that is around 5 months old (that is a guess.  I got him at the end of July and he was really small) and is about 11 inches long from nose to tip of tail.  When we first got him he ate like crazy.  Now, he doesn't seem to want to eat at all.  We feed him meal worms, small super worms, crickets and wax worms.  I try to feed him different vegetation but the only thing he eats is romaine lettuce which I know has no vitamin supplementation for him.  I do normally dust his food with flukers calcium with vitamin d.  He is in a 20 gallon tank.  He has a zilla uv lamp with a 15 watt uv bulb. He has a heat lamp with a 100 watt bulb in it and another lamp with a 75 watt red bulb for at night.  the warm side of the tank stays between 90-100.  the cool side is around 70.  We use newspaper for the bottom of the tank and there is a water bowl and stuff for him to climb on and hide under in the tank. We spray the tank every few days.  
For the past week I have noticed that he really does not want to eat.  He might eat 3-4 meal worms but that is it.  Also, he usually would sit on top of the log under the lamp and look around all day.  Now I have noticed that he hides under stuff and just lays there all day.  I have even found him burrowed under the newspaper.  I am not sure if he is sick or I was reading some information that made me think he might be going through a dormant phase.  Any suggestions or comments would be helpful.  Thanks

Answer
Hello Nicole,

I would try changing your UVB tube light out first.  Those UVB lights are often hazardous & do not emit the proper UVB frequency wavelength to help them synthesize D3.  He could be having some calcium issues, perhaps.  
I would continue with the calcium supplementation, 5 times per week.  I would purchase the Reptisun 10 tube bulb to see if that will help him out.  Is your basking bulb a bright white light & mounted directly beside the tube bulb now?  How close is it to him?
The red bulb at night, may be disturbing his sleep patterns.  They can see the red spectrum.  I would use a ceramic heat emitter at night, if you need nighttime heating.  It only emits heat but no light.  
Do you have any pictures of him right now?
What type of thermometer do you use to measure the temperatures?
He could be exhibiting signs of brumation, but let's rule everything else out first.  Try purchasing the Reptisun 10 tube bulb from  www.petmountain.com  first & see if there are any improvements.

Let me know how he is doing.

Tracie