He looks pretty good, all things considered. Do you have any idea how old he is, or did I miss that? If that's a 20 gallon tank (it actually looks larger than that in the photo, at least to me), then it's either way too small for him already or else he's going to outgrow it in no time. Also, if you get him a new UV light, the one most often recommended is the Reptisun 10.0 fluorescent tube -- the T5 HO (High Output) version can be used on top of a screen top and enough will still get through. The coil type UV bulbs have a bad reputation and are usually not recommended. (You probably already know that proper UV light is very important for vitamin D and calcium metabolism to maintain bone health.)
I also agree that you should get rid of the sandy substrate ASAP, especially if it contains any walnut shells. Plain white paper towels are another good alternative -- they're cheap, safe, and disposable -- it's easy to spot messes when they happen and easy to clean up.
And thanks for raising the issue about humidity and thanks for all the info, Kingofnobbys and everyone else. In all my research :study: I've never been able to find anything definite about the optimum humidity range for bearded dragons, although I assumed that they needed it on the dry side since they're desert critters. We've got the opposite problem here in Alaska -- in the winter the indoor air gets really REALLY dry -- the thermometer/hygrometer probes in my beardie's tank often read between 0 (at the basking site under the heat lamps) to around 30% at the cooler end. We keep an upside down frisbee in his tank for a water dish and a little evaporation (although we've never seen him drink from it), we serve his veggies with water (keeps them fresher longer and helps with
hydration if he eats them), and we
bathe him almost every day and dribble water on his nose in the
bath (sometimes he drinks it), so we hope he has plenty of opportunities to stay well enough
hydrated.
It's nice to find out that beardies can apparently deal with a wide range of humidity from dry to wet and everything in between.