Im sure this is answered a bunch here on these threads but I cant seem to find it.
I have a 24" reptisun t5 10.0 in a reflector. It sits about 13" above my beardies basking rock. Today I decided to cut the screen out under T5 to allow more UVB. Now i'm worried this might be too much UVB. I have an Exo-terra 40 breeder. 36" wide 24" tall and 18" deep.
I put this together based on Arcadia guidelines, and data provided my some manufacturers : viewtopic.php?f=34&t=235611
I am for 180 - 200 microW UVB flux / sq.cm at the basking spot for bearded dragons, and 100 microW UVB flux / sq.cm elsewhere.
A good approximation for a 10%UVB T5H0 tube is to take the graph microW UVB flux/sq.cm against distance for the 12%UVB T5HO tube and adjust them distance for a given UVB flux by multiplying bhy 10/12.
For your equipment 12-16” from the basking site will have very reasonable basking levels of UV. Any closer than 10” is going to be very strong and not suitable for such a small cage.
With the screen 10-14” away would have a similar level of UV.
You have it all just right for him, at 13 inches it should be perfect unobstructed! The T5
tubes are very good so your dragon will be getting some great UVB exposure.