Hi I have a 2 year old bearded dragon who is about 18 inches long. He is recently developed a illness that I believe is a respirtory infection. I have heard him wheeze some nights but not all the time. His eyes during the day sometimes bulge out of his head and it almost gives me a heart attack every time. He also hiccups alot during the day. I am very worried about him. His enclosure is a 40 gallon tank but i am tommorow going to petsmart and buyin him the biggest terrarium they have. His substrate is ground walnut shells witch i am skeptical of. For his heating light I use a normal 100 Watt light bulb. Is this ok? For his UVB light I use a Exotherra Repti-Glo 10.0 bulb not the tube. At the hot end of his tank (where he stays most of the day) it gets about 92 degrees. At night i use a under heating pad and the temps stay around 70-75 degrees. He still has a pretty hearty appetite. I feed him about 4 large crickets a day witch i dust 3x a week in calcium powder. He is also fed mustard greens, squash and