hey buddy im just going to fire out a few things here that i would do if i was you.
get rid of the sand. Put tiles in there or paper (i use double sided sticky tape to stick the paper down) Don't use tiles, theres no grip and it will stress your beardie out
get rid of anything covering your basking bulb. I would get a proper thermometer and get the basking spot to 110. Don;t let your dragons get within 5 inches of this bulb as it can burn them very badly if they jump at it
use a reptisun10 or arcadia 12 uvb tube. You will need to move the fixture inside the tank as it is too far away. 7-9inches is perfect. Otherwise the dragon will not get the uvb benefit and this is very very bad.
Feed him small crix. nothing else. After he has warmed up for an hour or so drop your crickets in and do the same later in the day. Put fresh cut beans and vegies (no lettuces or avocado) on the cool side of the tank.
Give your dragons a bath 2 times a week in warm shoulder deep water. Keep your eyes on them at all times. If they poop in the water change the water. They get hydration from this. this is too much, you risk a POSSIBLE URTI which will make your dragon very sick. he will get plenty of water from fruit and veg if given the correct nutrition
In time you will have to seperate your dragons. I know you dont want to hear this but it is a fact that all dragons have dominance issues.
Dont use any fans or anything like that. Just get your basking spot at 110 and let the dragon do the rest by regulating their temps. I would use a 60w bulb for your set up.Sorry, i disagree with this as well. fans can benefit if you are struggling to get the cool ends temp down.