Hi -
My advice is to spend $25 on a temp-gun instead. (www.tempgun.com). Cyrus is in a 2'x2'x4'tall all screen cage (2 sides have about 3 inches of space b/t it and wall of "closet"
all sides but front have plastic shower curtain (this is mainly for moisture retention but helps with heat, too.
I have one 100w incandescent bulb in a large dome that sits on top (bulb is far enough away so he cannot get burned) and one UVB strip light. Not sure the dims of a 65 gal but you really should need another heat source. The temp gun is great to get TRUE readings of basking spot and then other places. Colors change due to stress, temps, illness, sleep, etc. You also want about a 10 degree drop at night.
here is a pic of Luna's old setup - similar to what I have now - and the next is Cyrus' setup before he moved to the big cage (from a 20"x20"x18" - approx)


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Chameleon Help & Resource Info
1.0 Nosy Be Panther Chameleon - Cyrus
0.1 Veiled Chameleon - Luna. She's now hanging from her big jungle gym in the sky
1.0 Beardie - Darwin
1.1.1 Side-blotched lizards - Ana and Stan
0.2 felines - Kyndra and Lita
0.1 African Clawed Frog - Skippy
0.1 Chilean Rose Hair Tarantula - Rosa Leigh, Died 4/21/06 
0.1 Goliath Bird-Eater Tarantula - Natasha, donated to science 4/4/06
?.? Pinktoe Tarantula - no name yet