6 month bearded dragon

Question
I've had my beardie for 1 month. I am using a full spectrum bulb for heat and I was told it had UVB.  With further research i've come to find out it does not have UVB.  I wondering what kind of damage this has caused my beardie since he has not had UVB for at least 1 month if at all since he has been born.  I am going to purchase a mercury bulb for him.  Do I need to worry about MBD at this point or will he be okay going forward with the proper UVB?  I do not notice anything wrong with him at this point.  Please let me know.  Also he has 40 gallon tank and the mercury bulb is 160Watt is that okay or should I get a 100Watt.  Thank you for all of your help.

Answer
The 100 watt would be better for a 40 gallon tank, and if you are going mercury vapor, I would suggest the Mega Ray which can only be ordered with the developer at ReptileUV,com.  I would also suggest getting a mesh reptarium or a leash (I use the Four Paws brand reptile leash, and getting him outside every day to get natural sun until the bulb comes in.  Also you can speak to Bob at ReptileUV and discuss the best bulb for your baby's needs, Bob is extremely helpful.
 Another thing is investing in a UVB Meter.  This way you can periodically check to make sure the bulb is emitting enough UVB.  Bob can also give you advice about this as well.
 Since I don't know the type of care your baby had before you got him I would say he may have a mild case of MBD.  Sunshine and a good calcium supplement will help.  He is still young and can recover.