Is my UVB too close?

Hi everyone, I'm not sure if my set up is correct for my Beardie.. Could anyone help me please? 20 Gallon Tank, Repticarpet, basking side ranges from 98-108 degrees, cool side is 80. he poops 2-3 times per day. I'm using a 18" reptisun 10.0 t8 tube UVB (7.5 inches from the dragon's basking spot), 100W basking bulb, my only concern right now is my UVB is too close? I even cut out a sliver in the mesh so that the light can penetrate more into the enclosure, as Iv'e heard tightly woven mesh can block out a lot of UVB. I only cut it because I was worried he was not getting enough UVB and was having minor arm/leg twitching. That has since stopped, but now I'm worried he is getting too much UVB? He closes his eyes quite often while basking. Here's a few pics, please excuse the dirty glass lol. its only on the outside. http://s1300.photobucket.com/user/19nick93z/media/securedownload%202_zpsjn8o20ez.jpg.html?sort=3&o=0

http://s1300.photobucket.com/user/19nick93z/media/securedownload_zpsarqrtrue.jpg.html?sort=3&o=1

http://s1300.photobucket.com/user/19nick93z/media/securedownload%201_zpsgrwr5img.jpg.html?sort=3&o=2

Your setup sounds good. The UVB isn't too close. You'll want it 6-8'' and cutting a hole in the mesh is a very good idea. I did that with my small tank too. When it's time to upgrade to a larger tank, I recommend getting a higher output T5 bulb and fixture. Until then, the T8 at that distance with a reflective fixture should be safe and effective. The T8 isn't powerful enough to cause too much exposure, especially at that distance. That said, It's always good to provide multiple hides so they can self regulate their exposure as needed.