Hi there,
I can spot a few things that may well be causing a lethargic dragon.
Firstly the coil
UVB bulb. Unfortunatly not only do these bulbs produce very poor UVB but they are actually hazardous to your dragons health. They are especially linked with eye problems in dragons.
I would remove it tonight and not turn it back on again until you get a new UVB.
The best
UVB bulb out there is the ReptiSun(not reptiglo) 10.0 strip bulb. You want to avoid any coils or compacts as they are all dreadful.
Your dragon needs to be within about 6=8 inches of the bulb to get good exposure.
To take the temperature accuratley you need to leave the probe directly on the basking site for 45 minutes before taking a reading.
You need a basking temperature of 95-105 for your aged dragon.
At night there should be nothing on as any light can disturb your dragons sleep, which can lead to a cranky and lethargic dragon.
Ditch any "night time" bulbs you have. Its a cracking con to sell red "infra red" bulbs for bearde ddragons as they DO disturb dragons sleep as they can sense the light.
Your night time temperatures can safely drop to around 65 without you needing any night time heating boost.
If you do need a boost in temps at night you need to buy a Ceramic Heat Emmiter. This is a plate shaped bulb that radiates out heat without producing any light.
Washed playsand is only advised for adult bearded dragons.
Babies and juvies are far too inquisative and often end up ingesting their sand, especially if they are fed in their enclosures.
Calcium sand unfortunatly can be fatal for dragons. No if ands or buts about it im afraid. Sand is enough of a risk on its own but calcium sand not only encorages your dragon to lick it but it actually solidifies if mixed with water. This can lead to awful and dangerous blockages in your dragons intestines.
So all in all get the sand out tonight.
For a juvie your safe substrates are:
Tiles
Kitchen roll/Paper towels
Shelf liner
Non adhesive vinyl tiles
Repti Carpet
Newspaper (although there is sometimes an ink transfere issue).
Until you get a long term solution I would replace your sand with paper towels for now.
So things to do right away:
Out with the
UVB bulb
Out with the sand
Buy a new bulb tomorrow or order one online tonight.
You will be amazed at the difference in your dragon when he gets his
UVB bulb.
Holly